title: Serbia and Montenegro

text: Its aspirations to be the sole legal successor state to SFR Yugoslavia were not recognized by the United Nations, following the passing of United Nations Security Council Resolution 777, which affirmed that the Socialist Federal Republic of Yugoslavia had ceased to exist, and the Federal Republic of Yugoslavia was a new state. All former republics were entitled to state succession while none of them continued SFR Yugoslavia's international legal personality. However, the government of Slobodan Milošević opposed any such claims, and as such, FR Yugoslavia was not allowed to join the United Nations.


title: Serbia and Montenegro

text: Throughout its existence, FR Yugoslavia had a tense relationship with the international community, as economic sanctions were issued against the state during the course of the Yugoslav Wars and Kosovo War. This also resulted in hyperinflation between 1992 and 1994. FR Yugoslavia's involvement in the Yugoslav Wars ended with the Dayton Agreement, which recognized the independence of the Republics of Croatia, Slovenia, and Bosnia and Herzegovina, as well as establishing diplomatic relationships between the states, and a guaranteed role of the Serbian population within Bosnian politics. Later on, growing separatism within the Autonomous Province of Kosovo and Metohija, a region of Serbia heavily populated by ethnic Albanians, resulted in an insurrection by the Kosovo Liberation Army, an Albanian separatist group. The outbreak of the Kosovo War reintroduced Western sanctions, as well as eventual Western involvement in the conflict. The conflict ended with the adoption of United Nations Security Council Resolution 1244, which guaranteed economic and political separation of Kosovo from FR Yugoslavia, to be placed under UN Administration. Kosovo declared independence in 2008.


title: Serbia and Montenegro

text: Economic hardship and war resulted in growing discontent with the government of Slobodan Milošević and his allies, who ran both Serbia and Montenegro as an effective dictatorship. This would eventually cumulate in the Bulldozer revolution, which saw his government overthrown, and replaced by one led by the Democratic Opposition of Serbia and Vojislav Koštunica, which also joined the UN.


title: Serbia and Montenegro

text: The Federal Republic of Yugoslavia ended in 2003 after the Federal Assembly of Yugoslavia voted to enact the Constitutional Charter of Serbia and Montenegro, which established the State Union of Serbia and Montenegro. As such, the name Yugoslavia was consigned to history. A growing independence movement in Montenegro, led by Milo Đukanović meant that the Constitution of Serbia and Montenegro included a clause allowing for a referendum on the question of Montenegrin independence, after a period of three years had passed. In 2006, the referendum was called, and passed, by a narrow margin. This led to the dissolution of the State Union of Serbia and Montenegro, and the establishment of the independent republics of Serbia and Montenegro, turning Serbia into a landlocked country. This can be considered the last act which finalized the dissolution of Yugoslavia.


title: Serbia and Montenegro

text: At the country's founding in 1992 following the breakup of the Socialist Federal Republic of Yugoslavia (SFR Yugoslavia), the country's official name was the "Federal Republic of Yugoslavia" (FR Yugoslavia), as it claimed to be the sole legal successor state of the SFR Yugoslavia. The United States and European Union member states referred to the country as "Serbia and Montenegro" as their governments viewed its claim to Yugoslavia's successorship as illegitimate.


title: Serbia and Montenegro

text: The 2003 constitution stated that the name of the state was simply "Serbia and Montenegro", dropping all claims to successorship of the SFR Yugoslavia.


title: Serbia and Montenegro

text: After the collapse of SFR Yugoslavia in the 1990s, the two Serb majority republics, Serbia and Montenegro, agreed to remain as Yugoslavia, and established a new constitution in 1992, which established the Federal Republic of Yugoslavia essentially as a rump state, with a population consisting of a majority of Serbs. The new state abandoned the Communist legacy: the red star was removed from the national flag, and the communist coat of arms was replaced by a new coat of arms representing Serbia and Montenegro. The new state also established the office of the president, held by a single person, initially appointed with the consent of the republics of Serbia and Montenegro until 1997 after which the president was democratically elected. The President of Yugoslavia acted alongside the Presidents of the republics of Serbia and Montenegro. Initially, all three offices were dominated by allies of Slobodan Milosevic and his Socialist Party of Serbia.


title: Serbia and Montenegro

text: On 26 December 1991, Serbia, Montenegro, and the Serb rebel-held territories in Croatia agreed that they would form a new "third Yugoslavia". Efforts were also made in 1991 to include SR Bosnia and Herzegovina within the federation, with negotiations between Miloševic, Bosnia's Serbian Democratic Party, and the Bosniak proponent of union – Bosnia's Vice-president Adil Zulfikarpašić taking place on this matter. Zulfikarpašić believed that Bosnia could benefit from a union with Serbia, Montenegro, and Krajina, thus he supported a union which would secure the unity of Serbs and Bosniaks. Miloševic continued negotiations with Zulfikarpašić to include Bosnia within a new Yugoslavia, however efforts to include the whole of Bosnia within a new Yugoslavia effectively terminated by late 1991 as Izetbegović planned to hold a referendum on independence while the Bosnian Serbs and Bosnian Croats formed autonomous territories. Violence between ethnic Serbs and Bosniaks soon broke out. Thus, FR Yugoslavia was restricted to the republics of Serbia and Montenegro, and became closely associated with breakaway Serb republics during the Yugoslav Wars.


title: Serbia and Montenegro

text: The FRY was suspended from a number of international institutions. This was due to the ongoing Yugoslav wars during the 1990s, which had prevented agreement being reached on the disposition of federal assets and liabilities, particularly the national debt. The Government of Yugoslavia supported Croatian and Bosnian Serbs in the wars from 1992 to 1995. Because of that, the country was under economic and political sanctions. War and sanctions resulted in economic disaster, which forced thousands of its young citizens to emigrate from the country.


title: Serbia and Montenegro

text: FR Yugoslavia acted to support Serbian separatist movements in breakaway states, including the Republic of Serbian Krajina and the Republika Srpska, and sought to establish them as independent Serbian republics, with potential eventual reintegration with FR Yugoslvia. However, the Government of FR Yugoslavia would treat these republics as separate entities, and gave unofficial, rather than active, aid by transferring control of units from the JNA to the secessionist movements. In this way, FR Yugoslavia avoided potential accusations of committing acts of aggression against the breakaway republics recognised by the international community. Slobodan Milošević, the President of Serbia, did not consider himself to be at war with the breakaway republics of Yugoslavia.


title: Serbia and Montenegro

text: Following the transfer of Yugoslav Army units, the state of FR Yugoslavia ceased to play an important military role in the Yugoslav Wars, barring conflicts on the border with Croatia, such as the Siege of Dubrovnik. It instead provided economic and political aid, to avoid provoking the international community further, and to preserve FR Yugoslavia as the republics of Serbia and Montenegro, rather than 'Greater Serbia.'


title: Serbia and Montenegro

text: In 1995, following Operation Storm, a military offensive by the Croatian Army, and NATO involvement in the Bosnian War, President Slobodan Milošević agreed to negotiate, as the Serbian position within Bosnia had become substantially worse. Under threat of economically crippling the Republika Srpska, he took over negotiating powers for all Serbian secessionist movements, as well as FR Yugoslavia. The ensuing Dayton Agreements, signed between representatives from the Federal Republic of Yugoslavia, the Republic of Bosnia and Herzegovina and the Republic of Croatia, resulted in each state being recognised as sovereign states. It also provided recognition for Serbian institutions and a rotating presidency within Bosnia and Herzegovina, and the Serbian populated areas of the former Socialist Republic of Bosnia were absorbed into Bosnia and Herzegovina. Thus the Yugoslav Wars ended, and Western sanctions on FR Yugoslavia were lifted. However, Slobodan Milošević would not achieve his dreams of admitting FR Yugoslavia to the United Nations as the successor state of SFR Yugoslavia, as an 'outer wall' of Western sanctions prohibited this.


title: Serbia and Montenegro

text: Following the adoption of economic sanctions by the international community against FR Yugoslavia, its economy experienced a collapse. Sanctions on fuel meant that fuel stations across the country ran out of petrol, and foreign assets were seized. The average income of inhabitants of FR Yugoslavia was halved from $3,000 to $1,500. An estimated 3 million Yugoslavs (Serbs and Montenegrins) lived below the poverty line, suicide rates increased by 22% and hospitals lacked basic equipment. Along with this, supply links were cut, which meant that the Yugoslav economy could not grow, and imports or exports needed for industries could not be obtained, forcing them to close. The crippled state of the Yugoslav economy also affected its ability to wage war, and after 1992, Yugoslavia had an extremely limited military role within the Yugoslav Wars, due to the JNA units being unable to operate without oil or munitions.


title: Serbia and Montenegro

text: On top of this, starting in 1992 and until 1994, the Yugoslav dinar experienced a major hyperinflation, leading to inflation reaching 313 million percent, the second worst hyperinflation in history. Many parts of FR Yugoslavia, including all of Montenegro, adopted the Deutsche Mark and Euro currencies instead of the Yugoslav dinar. Western sanctions crippled the Yugoslav economy, and prevented it from playing an active role in aiding Serb breakaway republics. Following the Dayton Agreement, the UN Security Council voted to lift most sanctions, but they were reissued following the outbreak of an Albanian insurgency in Kosovo. The lasting economic impact can be attributed to the eventual downfall of FR Yugoslavia and Slobodan Milošević's government, as well as a deeper desire in Montenegro to leave Yugoslavia.


title: Serbia and Montenegro

text: In the Autonomous Province of Kosovo and Metohija, a growing desire for independence emerged among the Albanian majority population. Already, an unrecognised Republic of Kosova had emerged with underground institutions. In 1996, the Kosovo Liberation Army, an Albanian militia promoting Kosovar independence, launched attacks against Serbian police stations, killing at least ten Serbian policemen in direct attacks between 1996 and 1998. The low level insurgency eventually escalated. After Slobodan Milošević was elected President of Yugoslavia in 1997, having served his maximum two terms as President of Serbia, he ordered JNA units to move into Kosovo to aid in the suppression of the insurrection. The governments of FR Yugoslavia and the US declared the Kosovo Liberation Army a terrorist organisation, following repeated deadly attacks against Yugoslav law enforcement agencies. US intelligence also mentioned illegal arms sources of the Kosovo Liberation Army, including conducting raids during the course of the Albanian Civil War, and drug dealing. Despite this, substantial evidence now shows that the CIA had aided in training units of the KLA, although not necessarily providing them with arms and funding.


title: Serbia and Montenegro

text: In 1998, the Kosovo War began, following increased open combat with Yugoslav police and JNA units deployed by Milošević. The KLA found itself heavily outnumbered and outgunned in open combat, and had to use guerrilla tactics. Serbian police and JNA units attacked KLA outposts, attempting to destroy them, as KLA units attempted to avoid direct confrontation and use terrorist attacks, including bombings and ambushes, to weaken Yugoslav control. Although unable to gain a strategic advantage, Yugoslav Army units found themselves in a tactical advantage against KLA units which lacked proper training. JNA units themselves lacked morale, and attacks were often directed against civilian targets rather than military targets. 863,000 Albanian civilians were forcibly expelled between March and June 1999 from Kosovo. 169,824 Serb and Romani civilians were estimated by the UNHCR's Belgrade office to have fled from Kosovo to Serbia and Montenegro by 20 June 1999. Out of 10,317 civilians, 8,676 Albanians, 1,196 Serbs and 445 Roma, Bosniaks, Montenegrins and others were killed or went missing in connection with the war between 1 January 1998 - 31 December 2000. The Serbian government attributed 1,953 Serbian, 361 Albanian and 266 other civilian deaths or disappearances from 1 January 1998 - 1 November 2001 to “Albanian terrorism in Kosovo-Metohija”.


title: Serbia and Montenegro

text: The international community was quick to respond, issuing a peace proposal to Yugoslavia in 1999. The agreement was seen as an essential ultimatum by NATO to Yugoslavia, and this rejected by the Yugoslav government. NATO responded in March 1999 by ordering airstrikes against Yugoslav military targets and infrastructure, including roads, railroads, administrative buildings and the headquarters of Radio Television Serbia. NATO's bombing campaign was not approved by the UN Security Council, for fear of a veto by Russia, which would cause controversy as to its legality. The UN Security Council adopted United Nations Security Council Resolution 1160, renewing arms and oil sanctions against FR Yugoslavia, and thus crippling its economy. The effects of continuous aerial bombardment and sanctions cost the Yugoslav economy hundreds of billions of USD and eventually forced Milošević's government to comply with an agreement put forward by an international delegation. United Nations Security Council Resolution 1244 led to substantial autonomy for Kosovo, and the establishment of a UN mission to Kosovo, as well as the complete withdrawal of units of the Yugoslav National Army. As such, Kosovo remained an Autonomous Province of Serbia, but politically and economically independent. The damage to FR Yugoslavia was immense, with the government estimating $100 billion in infrastructure damage, as well as 1,200 Serbian and Albanian civilians or soldiers confirmed dead. Economists have estimated at least $29 billion in direct damages caused by the bombings.


title: Serbia and Montenegro

text: In the aftermath of the Kosovo War, a low level insurgency continued in parts of Southern Serbia, which had Albanian minorities. However, this insurgency lacked international support, and the Yugoslav Armed Forces were able to put down the insurgency.


title: Serbia and Montenegro

text: The string of defeats, as well as a complete collapse of the Yugoslav economy, led to mass unpopularity of the essential dictatorship of Slobodan Milošević and his allies in the Socialist Party of Serbia. In September 2000, amongst accusations of electoral fraud, large scale protests struck the nation. Milošević was eventually removed from power, as his Socialist Party of Serbia lost in the federal elections to the Democratic Opposition of Serbia. In the aftermath, a new government in Yugoslavia negotiated with the United Nations, accepting that it was not the sole legal successor to the Socialist Federal Republic of Yugoslavia, and was allowed to join the UN. Milošević would later be put on trial for corruption and war crimes, especially during the International Criminal Tribunal for the former Yugoslavia, although he died in prison before his trial could end in 2006. His culpability, especially of the charges brought against him in the context of the ICTY, remains a subject of controversy within Serbia.


title: Serbia and Montenegro

text: In 2002, Serbia and Montenegro came to a new agreement regarding continued co-operation, which, among other changes, promised the end of the name Yugoslavia (since they were part of the Federal Republic of Yugoslavia). On 4 February 2003, the Federal Assembly of Yugoslavia created a loose state union or confederacy—the State Union of Serbia and Montenegro, although Yugoslavia was still commonly used. A new constitutional charter was agreed to provide a framework for the governance of the country.


title: Serbia and Montenegro

text: On Sunday, 21 May 2006, Montenegrins voted in an independence referendum, with 55.5% supporting independence. Fifty-five percent or more of affirmative votes were needed to dissolve the confederation and Yugoslavia. The turnout was 86.3% and 99.73% of the more than 477,000 votes cast were deemed valid.


title: Serbia and Montenegro

text: The subsequent Montenegrin proclamation of independence on 3 June 2006 and the Serbian proclamation of independence on 5 June ended the confederation of Serbia and Montenegro and thus the last remaining vestiges of the former Yugoslavia.


title: Serbia and Montenegro

text: The Federal Assembly of Yugoslavia, representing FR Yugoslavia (1992–2003) was composed of two chambers: the Council of Citizens and the Council of Republics. Whereas the Council of Citizens served as an ordinary assembly, representing the people of FR Yugoslavia, the Council of Republics was made equally by representatives from the federation's constituent republics, to ensure federal equality between Serbia and Montenegro.


title: Serbia and Montenegro

text: The first president from 1992 to 1993 was Dobrica Ćosić, a former communist Yugoslav partisan during World War II and later one of the fringe contributors of the controversial Memorandum of the Serbian Academy of Sciences and Arts. Despite being head of the country, Ćosić was forced out of office in 1993 due to his opposition to Serbian President Slobodan Milošević. Ćosić was replaced by Zoran Lilić who served from 1993 to 1997, and then followed by Milošević becoming Yugoslav President in 1997 after his last legal term as Serbian president ended in 1997. FR Yugoslavia was dominated by Milosevic and his allies, until the presidential election in 2000. There were accusations of vote fraud and Yugoslav citizens took to the streets and engaged in riots in Belgrade demanding that Milošević be removed from power. Shortly afterwards Milošević resigned and Vojislav Koštunica took over as Yugoslav president and remained president until the state's reconstitution as the State Union of Serbia and Montenegro.


title: Serbia and Montenegro

text: Federal Prime Minister Milan Panić became frustrated with Milošević's domineering behaviour during diplomatic talks in 1992, and told Milošević to "shut up" because Milošević's position was officially subordinate to his position. Milošević later forced Panić to resign. However, this situation changed after 1997 when Milošević's second and last legal term as Serbian President ended. He then had himself elected Federal President, thus entrenching the power that he already de facto held.


title: Serbia and Montenegro

text: After the federation was reconstituted as a State Union, the new Assembly of the State Union was created. It was unicameral and was made up of 126 deputies, of which 91 were from Serbia and 35 were from Montenegro. The Assembly convened in the building of the old Federal Assembly of Yugoslavia, which now houses the National Assembly of Serbia.


title: Serbia and Montenegro

text: In 2003, after the constitutional changes and creation of the State Union of Serbia and Montenegro, a new President of Serbia and Montenegro was elected. He was also president of the Council of Ministers of Serbia and Montenegro.


title: Serbia and Montenegro

text: Svetozar Marović was the first and last President of Serbia and Montenegro until its breakup in 2006.


title: Serbia and Montenegro

text: The Armed Forces of Yugoslavia (Serbian: Војска Југославије/Vojska Jugoslavije, ВЈ/VJ) included ground forces with internal and border troops, naval forces, air and air defense forces, and civil defense. It was established from the remnants of the Yugoslav National Army (JNA), the military of SFR Yugoslavia. Several Bosnian Serb units of the VJ were transferred over to the Republika Srpska, during the course of the Bosnian War, leaving only units directly from Serbia and Montenegro in the armed forces. The VJ saw military action during the Yugoslav Wars, including the Siege of Dubrovnik and the Battle of Vukovar, as well as the Kosovo War, and played combat roles during ethnic insurgencies. Following the Kosovo War, the VJ was forced to evacuate Kosovo, and in 2003 it was renamed the <nowiki>"Armed Forces of Serbia and Montenegro."</nowiki> Following the dissolution of the Union between Serbia and Montenegro, units from each army were assigned to the independent republics of Serbia and Montenegro, as recruitment in the army was on a local, rather than Federal, level. Montenegro inherited the small navy of FR Yugoslavia, due to Serbia being landlocked.


title: Serbia and Montenegro

text: FR Yugoslavia was composed of four principal political units, consisting of two Republics, and two subordinate Autonomous Provinces, as following:


title: Serbia and Montenegro

text: The territorial organisation of the Republic of Serbia was regulated by the Law on Territorial Organisation and Local Self-Government, adopted in the Assembly of Serbia on 24 July 1991. Under the Law, the municipalities, cities and settlements make the bases of the territorial organization.


title: Serbia and Montenegro

text: Serbia was divided into 195 municipalities and 4 cities, which were the basic units of local autonomy. It had two autonomous provinces: Kosovo and Metohija in the south (with 30 municipalities), which was under the administration of UNMIK after 1999, and Vojvodina in the north (with 46 municipalities and 1 city). The territory between Kosovo and Vojvodina was called Central Serbia. Central Serbia was not an administrative division on its own and had no regional government of its own.


title: Serbia and Montenegro

text: In addition, there were four cities: Belgrade, Niš, Novi Sad and Kragujevac, each having an assembly and budget of its own. The cities comprised several municipalities, divided into "urban" (in the city proper) and "other" (suburban). Competences of cities and their municipalities were divided.


title: Serbia and Montenegro

text: Municipalities were gathered into districts, which are regional centres of state authority, but have no assemblies of their own; they present purely administrative divisions, and host various state institutions such as funds, office branches and courts. The Republic of Serbia was then and is still today divided into 29 districts (17 in Central Serbia, 7 in Vojvodina and 5 in Kosovo, which are now defunct), while the city of Belgrade presents a district of its own.


title: Serbia and Montenegro

text: Serbia and Montenegro had an area of 102,350 square kilometres (39,518 sq mi), with 199 kilometres (124 mi) of coastline. The terrain of the two republics is extremely varied, with much of Serbia comprising plains and low hills (except in the more mountainous region of Kosovo and Metohija) and much of Montenegro consisting of high mountains. Serbia is entirely landlocked, with the coastline belonging to Montenegro. The climate is similarly varied. The north has a continental climate (cold winters and hot summers); the central region has a combination of a continental and Mediterranean climate; the southern region had an Adriatic climate along the coast, with inland regions experiencing hot, dry summers and autumns and relatively cold winters with heavy snowfall inland.


title: Serbia and Montenegro

text: Belgrade, with its population of 1,574,050, is the largest city in the two nations: and the only one of significant size. The country's other principal cities were Novi Sad, Niš, Kragujevac, Podgorica, Subotica, Pristina, and Prizren, each with populations of about 100,000–250,000 people.


title: Serbia and Montenegro

text: FR Yugoslavia had more demographic variety than most other European countries. According to the 1992 census, the Federal Republic had 10,394,026 inhabitants. The three largest named nationalities were Serbs (6,504,048 inhabitants, or 62.6%), Albanians (1,714,768 inhabitants, or 16.5%), and Montenegrins (519,766 inhabitants, or 5%). The country also had significant populations of Hungarians, ethnic Yugoslavs, ethnic Muslims, Romani, Croats, Bulgarians, Macedonians, Romanians, Vlachs, and others (under 1%). Most of the ethnic diversity was situated in the autonomous provinces of Kosovo and Vojvodina, where smaller numbers of other minority groups could be found. The large Albanian population was chiefly concentrated in Kosovo, with smaller populations in the Preševo Valley, and in the Ulcinj municipality in Montenegro. The "Muslim" (Slavic Muslims, including Bosniaks and Gorani) population lived mostly in the federal border region (mainly Novi Pazar in Serbia, and Rožaje in Montenegro). It is important to note that the Montenegrin population often considered themselves as Serbs.


title: Serbia and Montenegro

text: More than half of Kosovo's pre-1999 Serb population (226,000), including 37,000 Romani, 15,000 Balkan Muslims (including Ashkali, Bosniaks, and Gorani), and 7,000 other non-Albanian civilians were expelled to central Serbia and Montenegro, following the Kosovo War.


title: Serbia and Montenegro

text: According to a 2004 estimate, the State Union had 10,825,900 inhabitants. According to a July 2006 estimate, the State Union had 10,832,545 inhabitants.


title: Serbia and Montenegro

text: The state suffered significantly economically due to the breakup of Yugoslavia and mismanagement of the economy, and an extended period of economic sanctions. In the early 1990s, the FRY suffered from hyperinflation of the Yugoslav dinar. By the mid-1990s, the FRY had overcome the inflation. Further damage to Yugoslavia's infrastructure and industry caused by the Kosovo War left the economy only half the size it was in 1990. Since the ousting of former Federal Yugoslav President Slobodan Milošević in October 2000, the Democratic Opposition of Serbia (DOS) coalition government has implemented stabilization measures and embarked on an aggressive market reform program. After renewing its membership in the International Monetary Fund in December 2000, Yugoslavia continued to reintegrate with other world nations by rejoining the World Bank and the European Bank for Reconstruction and Development.


title: Serbia and Montenegro

text: The smaller republic of Montenegro severed its economy from federal control and from Serbia during the Milošević era. Afterwards, the two republics had separate central banks whilst Montenegro began to use different currencies – it first adopted the Deutsche Mark, and continued to use it until the Mark fell into disuse to be replaced by the Euro. Serbia continued to use the Yugoslav Dinar, renaming it the "Serbian Dinar".


title: Serbia and Montenegro

text: The complexity of the FRY's political relationships, slow progress in privatisation, and stagnation in the European economy were detrimental to the economy. Arrangements with the IMF, especially requirements for fiscal discipline, were an important element in policy formation. Severe unemployment was a key political and economic problem. Corruption also presented a major problem, with a large black market and a high degree of criminal involvement in the formal economy.


title: Serbia and Montenegro

text: Serbia, and in particular the valley of the Morava is often described as "the crossroads between the East and the West" – one of the primary reasons for its turbulent history. The valley is by far the easiest land route from continental Europe to Greece and Asia Minor.


title: Serbia and Montenegro

text: Major international highways going through Serbia were E75 and E70. E763/E761 was the most important route connecting Serbia with Montenegro.


title: Serbia and Montenegro

text: After the formation of the State Union of Serbia and Montenegro, the Yugoslav tricolour was to be replaced by a new compromise flag. Article 23 of the Law for the implementation of the Constitutional Charter stated that a law specifying the new flag was to be passed within 60 days of the first session of the new joint parliament. Among the flag proposals, the popular choice was a flag with a shade of blue in between the Serbian tricolor and the Montenegrin tricolor of 1993 through 2004. The color shade Pantone 300C was perceived as the best choice. However the parliament failed to vote on the proposal within the legal time-frame and the flag was not adopted. In 2004, Montenegro adopted a radically different flag, as its independence-leaning government sought to distance itself from Serbia. Proposals for a compromise flag were dropped after this and the Union of Serbia and Montenegro never adopted a flag.


title: Serbia and Montenegro

text: A similar fate befell the country's state anthem and coat-of-arms to be; the above-mentioned Article 23 also stipulated that a law determining the State Union's flag and anthem was to be passed by the end of 2003. The official proposal for a state anthem was a combination piece consisting of one verse of the former (now current) Serbian national anthem "Bože pravde" followed by a verse of the Montenegrin folk song, "Oj, svijetla majska zoro". This proposal was dropped after some public opposition, notably by Serbian Patriarch Pavle. Another legal deadline passed and no state anthem was adopted. Serious proposals for the coat of arms were never put forward, probably because the coat of arms of the FRY, adopted in 1994 combining Serbian and Montenegrin heraldic elements, was considered adequate.


title: Serbia and Montenegro

text: Thus, the State Union never officially adopted state symbols and continued to use the flag and national anthem of the Federal Republic of Yugoslavia by inertia until its dissolution in 2006.


title: Serbia and Montenegro

text: FR Yugoslavia, later Serbia and Montenegro, was considered by FIFA and UEFA to be the only successor-state of Yugoslavia. Football was experiencing major success during the 1980s and early 1990s; however, due to the imposed economic sanctions, the country was excluded from all international competitions between 1992 and 1996. After the sanctions were lifted, the national team qualified for two FIFA World Cups—in 1998 as FR Yugoslavia and in 2006 as Serbia and Montenegro. It also qualified for Euro 2000, as FR Yugoslavia.


title: Serbia and Montenegro

text: The 1998 World Cup appearance in France was accompanied with plenty of expectation and quiet confidence as the team was considered to be one of the tournament's dark horses due to being stacked with proven world-class players such as 29-year-old Predrag Mijatović, 33-year-old Dragan Stojković, 29-year-old Siniša Mihajlović, 28-year-old Vladimir Jugović, and 31-year-old Dejan Savićević, as well as emerging 19-year-old youngster Dejan Stanković, and tall 24-year-old target forwards Savo Milošević and Darko Kovačević. Another reason for heightened expectations was that this was the country's first major international appearance following the UN-imposed exile. However, the squad never managed to hit top gear—although it did make it out of the group, it got eliminated by the Netherlands via an injury-time goal in the round-of-16. Two years later at Euro 2000, nearly the same team again made it out of the group and was again eliminated from the tournament by the Netherlands, this time convincingly, 1–6, in the quarter finals.


title: Serbia and Montenegro

text: Serbia and Montenegro were represented by a single national team in the 2006 FIFA World Cup tournament, despite having formally split just weeks prior to its start. The final squad was made up of players born in both Serbia and Montenegro.


title: Serbia and Montenegro

text: They played their last ever international on 21 June 2006, a 3–2 loss to Ivory Coast. Following the World Cup, this team has been inherited by Serbia, while a new one was to be organized to represent Montenegro in future international competitions.


title: Serbia and Montenegro

text: The senior men's basketball team dominated European and world basketball during the mid-to-late 1990s and early 2000s, with three EuroBasket titles (1995, 1997, and 2001), two FIBA World Cup titles (1998 and 2002), and a Summer Olympic Games silver medal (1996).


title: Serbia and Montenegro

text: The national team started competing internationally in 1995, after a three-year exile, due to a UN trade embargo. During that time, FR Yugoslavia was not allowed to compete at the 1992 Summer Olympics in Barcelona, the 1993 EuroBasket, and also the 1994 FIBA World Championship, which was originally supposed to be hosted by Belgrade, before being taken away from the city and moved to Toronto, Canada.


title: Serbia and Montenegro

text: At the 1995 EuroBasket in Athens, its first international competition, the hungry and highly motivated FR Yugoslav team, which was led by head coach Dušan Ivković, featured a starting five full of world-class talent, with established European stars at positions one through four — 27-year-old Saša Đorđević, 25-year-old Predrag Danilović, 29-year-old Žarko Paspalj, 22-year-old Dejan Bodiroga — capped off with 27-year-old Vlade Divac, the starting center for the LA Lakers at the five position. With a bench that was just as capable — with experienced Zoran Sretenović (the only player over 30 in the team), Saša Obradović, talisman power forward Zoran Savić, and up-and-coming young center Željko Rebrača — the team rampaged through its preliminary group, which featured medal contenders Greece and Lithuania, with a 6–0 record. At the first direct elimination stage, the quarterfinals, FR Yugoslavia scored 104 points to destroy France, thus setting up a semifinal clash with the tournament hosts Greece. In the highly charged atmosphere of the OAKA Indoor Arena, the FR Yugoslav team demonstrated its versatility, using defensive prowess in that game to pull off a famous eight-point win, in a tense, low-scoring 60–52 game. In the final, FR Yugoslavia played against the experienced Lithuanian team, which was led by basketball legend Arvydas Sabonis, in addition to other world class players like Šarūnas Marčiulionis, Rimas Kurtinaitis, and Valdemaras Chomičius. The final became a classic game of international basketball, with the crafty Yugoslavs prevailing, by a score of 96–90, behind Đorđević's 41 points.


title: Serbia and Montenegro

text: They were represented by a single team at the 2006 FIBA World Championship as well, even though tournament was played in mid/late-August and early-September of that year, and the Serbia–Montenegro breakup had occurred in May. That team was also inherited by Serbia after the tournament, while Montenegro created a separate senior national basketball team afterwards, as well as their own national teams in all other team sports.


title: Serbia and Montenegro

text: Serbia and Montenegro was represented after its formal dissolution in the Miss Earth 2006 pageant by a single delegate, Dubravka Skoric.


title: Serbia and Montenegro

text: Serbia and Montenegro also participated in the Eurovision Song Contest on two occasions and in Junior Eurovision Song Contest 2005 only on one occasion. The country debuted in the Eurovision Song Contest under the name Serbia and Montenegro in 2004, when Željko Joksimović got second place. The next to follow was the Montenegrin boyband No Name. In 2006, the year of Montenegrin independence, the country Serbia and Montenegro did not have a representative due to the scandal in Evropesma 2006, but was still able to vote in both the semi-final and the final.


title: Julianna Margulies

text: Julianna Margulies (; born June 8, 1966) is an American actress. After several small television roles, Margulies achieved wide recognition for her starring role as Carol Hathaway on NBC's long-running medical drama series "ER" (1994–2009), for which she received a Primetime Emmy Award. In 2009, she took on the lead role of Alicia Florrick in the CBS legal drama "The Good Wife" (2009–2016). Her performance garnered acclaim, winning two Primetime Emmy Awards for Outstanding Lead Actress in a Drama Series, a Golden Globe Award, and a Television Critics Association Award.


title: Julianna Margulies

text: In 2021, she began portraying character Laura Peterson on the Apple TV+ drama series "The Morning Show", starring alongside Jennifer Aniston and Reese Witherspoon.


title: Julianna Margulies

text: Margulies had a recurring role on "The Sopranos" (2006-2007). She also voiced Neera in the adventure film "Dinosaur" (2000) and appeared in the miniseries "The Mists of Avalon" (2001). Her other films include "Evelyn" (2002), "Ghost Ship" (2002), "Snakes on a Plane" (2006), "City Island" (2009), "Stand Up Guys" (2012), and "The Upside" (2017). She also had starring roles in the AMC dark comedy series "Dietland" (2018) and the National Geographic miniseries "The Hot Zone" (2019).


title: Julianna Margulies

text: Margulies has won eight Screen Actor Guild Awards, making her the second most awarded woman ever within SAG after Julia Louis-Dreyfus, one Golden Globe Award, and three Primetime Emmy Awards. In 2015, "Time" magazine named her one of the 100 most influential people in the world. Margulies is also a recipient of a star on the Hollywood Walk of Fame.


title: Julianna Margulies

text: Julianna Margulies was born in Spring Valley, New York, the youngest of three daughters. Her mother Francesca ( Goldberg, later Gardner) was a ballet dancer and eurythmy teacher. Her father Paul Margulies was a writer, philosopher, and Madison Avenue advertising executive. Her parents were both Jewish, descendants of Ashkenazi Jewish immigrants from Romania, Austria, Hungary, and Russia. They divorced when she was a year old.


title: Julianna Margulies

text: In her memoir, "Sunshine Girl", Margulies wrote that her parents both adhered to the teachings of anthroposophy. Margulies, herself, has said that she does not hold religious beliefs, although she is ethnically Jewish and teaches the traditions to her son. In a 2013 interview, she said, “I would say if I had a religion, it would be gratitude…I love the tradition of Judaism that on Friday nights, Shabbat means 'Goodbye to the workweek; hello to family and the weekend.'”


title: Julianna Margulies

text: In her memoir, Margulies also wrote about her difficult, nomadic childhood. While she is from New York, she moved with her mother to many different countries and states throughout her youth, including Sussex, England and Paris, France. As a result, French was Margulies’ first language. She has since lost the ability to speak it fluently.


title: Julianna Margulies

text: In the book, Margulies described her childhood as ultimately loving, but unpredictable and unstable. She detailed many emotionally traumatic experiences.


title: Julianna Margulies

text: Margulies attended many different schools as a child, including Green Meadow Waldorf School and High Mowing School. She graduated with a degree in art history and English from Sarah Lawrence College, where she appeared in several campus plays. At Sarah Lawrence College, students select three areas of focus for coursework. Margulies focused on art history, English, and theatre. She originally enrolled in college with the goal of becoming a lawyer, like her grandmother, or a psychologist, but fell in love with the craft of acting.


title: Julianna Margulies

text: Margulies made her feature film debut in Steven Seagal's action film "Out for Justice" (1991), playing a sex worker. In 1994, Margulies was cast in the pilot episode of the NBC medical drama "ER" as Carol Hathaway, an emergency care nurse who attempted suicide. Her character was originally intended to die; however, test audiences overwhelmingly wanted her to survive, so the producers changed the plot and made Carol Hathaway a main cast member.


title: Julianna Margulies

text: At the time she was offered "ER", Margulies had also been offered an extended role on NBC's "", after a two-episode appearance earlier in the year. Then-unknown actor George Clooney, who had filmed the pilot episode with Margulies, called her to let her know that he had overheard producers saying that her character might survive the suicide attempt after all and become a series regular. He encouraged her to consider waiting for "ER" producers to call her and not take another job. Clooney was right and Margulies accepted the role on "ER" in 1994.


title: Julianna Margulies

text: She remained on the show as a series regular for six seasons until 2000 and returned to the show for one episode during its final season in 2009. She won a Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series in 1994, and continued to be nominated for an Emmy Award every year during her tenure on "ER". She was the only series regular cast member to win a Primetime Emmy Award. She was also nominated four times for a Golden Globe Award during the show’s tenure.


title: Julianna Margulies

text: Originally, Margulies had signed a 5-year contract to work on "ER". She extended the contract for a sixth year, but made the “very difficult, painful decision” to opt out of another renewal. In 2021, she explained in her memoir, "Sunshine Girl", that she had been feeling homesick for New York after spending six years filming the show in Los Angeles. She wanted to return to theatre and take on a leading role in The Mists of Avalon, a miniseries based on a favorite childhood book.


title: Julianna Margulies

text: In 2021, Margulies said during an interview with Michael Imperioli and Steve Schirripa, “I thought, didn’t I work six years on a show I loved — I loved being on "ER", I was so grateful, and it was a great experience — but didn’t I work this hard to be able to do theatre for $235 a week without worrying about my rent?” She explained that, before NBC offered her a shocking $27 million to sign on for another two years, she had already helped plan out the conclusion of her character’s story arc on the show and mapped out a year’s worth of work for herself.


title: Julianna Margulies

text: In a New York Times interview with Bill Carter, Margulies shared that another factor in her decision was a desire to protect her "ER" character, Carol Hathaway, from certain story changes that were happening as the show continued on into later years. She explained that she didn’t like how her character became the focus of too much romance whenever she wasn’t with George Clooney’s character, and that all of the research she had previously done in order to play the character was then undone by certain storylines.


title: Julianna Margulies

text: Margulies recalled, “I’ll never forget, there was a line [in the script] where [my character] says, ‘I had to share a bathroom with seven sisters.’ I was like, guys, I’ve been playing her as an only child for six years…I had actually done research on what it’s like to be an only child. I was starting to feel very sad about a character I loved so much. It started to become very clear to me that without George, my character was just going to be the liaison to flashy sort of bits of things instead of one fluent, cognizant thought and I felt sad about it.”


title: Julianna Margulies

text: If Margulies had accepted the $27 million contract for a seventh and eighth year of ER, it would have made her one of the highest paid women on television. The actress said that she received intense, hurtful backlash for her decision to ultimately leave "ER", but was “doing what fed me, as an actor,” she said in 2021. “And keeping my promises to playwrights and directors who I’d already made a commitment to.”


title: Julianna Margulies

text: Margulies had previously broken her silence on her decision in 2012. She revealed that although everyone said it would be "career suicide" not to return to the medical drama, she was never concerned about the consequences:


title: Julianna Margulies

text: In an interview with "TV Guide", she further explained, "I felt like I had a great character and I did as much as I could do with her, but I was feeling bored. I wasn't excited about the work and I certainly didn't want to go out with a bomb, but as an inspiration."


title: Julianna Margulies

text: In February 2000, Margulies hosted an episode of the NBC late-night sketch series "Saturday Night Live". She brought on "ER" co-star Noah Wyle for one of the show’s sketches.


title: Julianna Margulies

text: After leaving "ER" as a series regular, Margulies worked on stage and screen. On stage, she appeared in a MCC Theater production of Kate Robin's "Intrigue With Faye", a Lincoln Center production of Jon Robin Baitz's "Ten Unknowns", and "The Vagina Monologues".


title: Julianna Margulies

text: Her work after "ER" included the 2002 films "Evelyn", with Pierce Brosnan, and "Ghost Ship", with Gabriel Byrne and Ron Eldard. She starred as Morgaine, the protagonist and narrator of the TNT miniseries "The Mists of Avalon" (2001) and participated in the documentary film "Searching for Debra Winger" (2002).


title: Julianna Margulies

text: In 2004, she guest-starred in a two-episode arc in season four of the hit NBC comedy series "Scrubs" as Neena Broderick, an unscrupulous lawyer who sues Turk and has a brief sexual relationship with J.D. That same year, she starred in another miniseries on TNT, "The Grid". In April 2006, she appeared in four episodes of the sixth season of the HBO crime drama series "The Sopranos", portraying realtor Julianna Skiff. In August 2006, she appeared alongside Samuel L. Jackson in the action film "Snakes on a Plane", as flight attendant Claire Miller. In December 2006, she played Jennifer Bloom in the Syfy Channel miniseries "The Lost Room".


title: Julianna Margulies

text: In an August 2006 interview with tvguide.com, Margulies said she was close to accepting an offer to return to "ER" for a four-episode arc, with Noah Wyle, that filmed in Hawaii during the 2005/06 season. However, she decided against it at the last minute. "I left on very good terms with ["ER" exec producer] John Wells, and every year they ask me back and I love that they do," she told "TV Guide" in 2006. "So, at the last minute, I went, 'John, thank you and keep asking, because you never know, but no.'"


title: Julianna Margulies

text: Margulies was invited to return during "ER"'s final season. The actress hesitated, saying she felt like she left Carol Hathaway in the perfect place and could not imagine bettering her departure episode, but Margulies did return to "ER" for one more episode during its 15th and final season.


title: Julianna Margulies

text: In a 2013 interview, she said of her appearance, “I called George up and said, ‘If you do it, I’ll do it.’ We were both very aware we had careers because of that show, and we also loved those characters. I remember walking on to the Warner Brothers lot, and they asked for my ID. I used to have my picture on the wall there. It was a little surreal, but a lovely way to come full circle.”


title: Julianna Margulies

text: Margulies had a minor role in the film "The Darwin Awards" (2007). In 2008, Margulies starred in the legal series "Canterbury's Law", a Fox mid-season replacement show. She played the title character, Elizabeth Canterbury, a lawyer. She was also credited as a producer of the show. The series was severely affected by the 2007–2008 Writers Guild of America strike; it was cancelled by the network after only six episodes.


title: Julianna Margulies

text: In 2009, after returning to "ER" for one episode during its 15th and final season, Margulies began starring in the CBS legal drama series "The Good Wife". She played Alicia Florrick, an attorney returning to legal practice after her husband Peter Florrick (played by Chris Noth) resigned as Illinois State's Attorney amid a sex and corruption scandal. She won two Primetime Emmy Awards and a Golden Globe Award for the series. Beginning in 2011, starting with the third season, Margulies was credited as a producer of "The Good Wife". The series ended in May 2016.


title: Julianna Margulies

text: Reflecting on her roles as Alicia on "The Good Wife" and as Carol on "ER", Margulies told "Entertainment Weekly" in 2021, “I have gotten to play two of the richest, I think, female characters on television.” In a 2019 interview for the Series Mania Festival, Margulies said that "it's tied between Carol Hathaway and Alicia Florrick" when it comes to the role she is most proud of having played.


title: Julianna Margulies

text: Since 2013, the actress has done voiceovers for a Chase credit card commercial. In 2014, Margulies narrated "Women in Business", an episode of season 2 of the documentary series "". In 2015, "TIME" featured Margulies as one of the "100 Most Influential People in the World". It noted her work to get Erin's Law, concerned with child sexual abuse, passed in every US state.


title: Julianna Margulies

text: In 2018, Margulies co-starred in the dark comedy series "Dietland" on AMC as Kitty Montgomery—a nasty, razor-thin fashionista who employs an overweight woman for menial tasks and enjoys torturing her constantly (especially about her weight). Despite positive reviews, the series was cancelled after one season.


title: Julianna Margulies

text: In 2019, Margulies starred in the National Geographic series "The Hot Zone", as Dr. Nancy Jaax—a U.S Army scientist Nancy Jaax, DVM, ACVP, trying to stop a deadly outbreak of Ebola. The limited series put up large rating numbers for the Disney-owned cable network, becoming the highest-rated scripted series in National Geographic's history and ranking second among all series.


title: Julianna Margulies

text: In 2019, Margulies was slated to reprise the role of Alicia Florrick for three episodes of "The Good Fight", a spin-off of "The Good Wife". However, negotiations broke down over the question of Margulies' salary, with CBS offering to pay her at the guest star rate instead of the same rate she had been paid on "The Good Wife". She stated that: "I watch the show, I love the show. But I'm not a guest star. You don't pay me a guest-star salary. I would get a guest-star salary if I went and did —it's not my show. I wouldn't ask for what I got paid as Alicia Florrick. I also know for a fact that any male star who got asked to go on a spinoff of his show would have been offered at least $500,000. I know that for a fact."


title: Julianna Margulies

text: In November 2019, Margulies guest starred in the Showtime drama series "Billions". She played Catherine Brant, who is described as an Ivy League sociology professor and bestselling author.


title: Julianna Margulies

text: In December 2020, Margulies joined the second season of the AppleTV+ drama series "The Morning Show" as Laura Peterson, an anchor at UBA News. She joined returning series stars Jennifer Aniston and Reese Witherspoon.


title: Julianna Margulies

text: In 2021, Margulies appeared with many of her former "ER" cast members in a virtual cast reunion show that benefited the Waterkeeper Alliance charity.


title: Julianna Margulies

text: Margulies published a picture book with Random House Children's Books in May 2016. Titled "Three Magic Balloons", the story is based on one that the actress's father, Paul Margulies, wrote for her and her sisters.


title: Julianna Margulies

text: In October 2020, Margulies announced on her Instagram that she was writing an autobiography, "Sunshine Girl: An Unexpected Life", published by Ballantine Books. She had originally intended to write an acting handbook about set etiquette, but ended up writing a memoir, instead. The book chronicles her nomadic childhood and journey to becoming an actress. Her book was released on May 4, 2021. Margulies also recorded the audiobook. A paperback version with additional chapters is set to be released in May 2022.


title: Julianna Margulies

text: From 1991 to 2003, Margulies was in a relationship with actor Ron Eldard, whom she met in an acting class.


title: Julianna Margulies

text: On November 10, 2007, Margulies married attorney Keith Lieberthal, the son of academic Kenneth Lieberthal, in Lenox, Massachusetts. They have a son, Kieran Lindsay Lieberthal. They reside in Manhattan. The couple also owns a country house in Upstate New York.


title: Julianna Margulies

text: Margulies is on the board of the MCC Theater Company in New York City. She is also a supporter of research on amyotrophic lateral sclerosis through Project ALS, as well as Erin’s Law. In 2022, she hosted the Physicians for Human Rights virtual gala, “A Celebration of Health and Human Rights Heroes”.


title: Nitrogen

text: Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N, a colorless and odorless diatomic gas. N forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere.


title: Nitrogen

text: Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives), and cyanides, contain nitrogen. The extremely strong triple bond in elemental nitrogen (N≡N), the second strongest bond in any diatomic molecule after carbon monoxide (CO), dominates nitrogen chemistry. This causes difficulty for both organisms and industry in converting N into useful compounds, but at the same time it means that burning, exploding, or decomposing nitrogen compounds to form nitrogen gas releases large amounts of often useful energy. Synthetically produced ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems.


title: Nitrogen

text: It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name "nitrogène" was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790 when it was found that nitrogen was present in nitric acid and nitrates. Antoine Lavoisier suggested instead the name "azote", from the "no life", as it is an asphyxiant gas; this name is used in several languages, including French, Italian, Russian, Romanian, Portuguese and Turkish, and appears in the English names of some nitrogen compounds such as hydrazine, azides and azo compounds.


title: Nitrogen

text: Apart from its use in fertilisers and energy stores, nitrogen is a constituent of organic compounds as diverse as Kevlar used in high-strength fabric and cyanoacrylate used in superglue. Nitrogen is a constituent of every major pharmacological drug class, including antibiotics. Many drugs are mimics or prodrugs of natural nitrogen-containing signal molecules: for example, the organic nitrates nitroglycerin and nitroprusside control blood pressure by metabolizing into nitric oxide. Many notable nitrogen-containing drugs, such as the natural caffeine and morphine or the synthetic amphetamines, act on receptors of animal neurotransmitters.


title: Nitrogen

text: Nitrogen compounds have a very long history, ammonium chloride having been known to Herodotus. They were well-known by the Middle Ages. Alchemists knew nitric acid as "aqua fortis" (strong water), as well as other nitrogen compounds such as ammonium salts and nitrate salts. The mixture of nitric and hydrochloric acids was known as "aqua regia" (royal water), celebrated for its ability to dissolve gold, the king of metals.


title: Nitrogen

text: The discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford in 1772, who called it "noxious air". Though he did not recognise it as an entirely different chemical substance, he clearly distinguished it from Joseph Black's "fixed air", or carbon dioxide. The fact that there was a component of air that does not support combustion was clear to Rutherford, although he was not aware that it was an element. Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as "burnt air" or "phlogisticated air". French chemist Antoine Lavoisier referred to nitrogen gas as "mephitic air" or "azote", from the Greek word (azotikos), "no life", due to it being asphyxiant. In an atmosphere of pure nitrogen, animals died and flames were extinguished. Though Lavoisier's name was not accepted in English since it was pointed out that all gases but oxygen are either asphyxiant or outright toxic, it is used in many languages (French, Italian, Portuguese, Polish, Russian, Albanian, Turkish, etc.; the German "Stickstoff" similarly refers to the same characteristic, viz. "ersticken" "to choke or suffocate") and still remains in English in the common names of many nitrogen compounds, such as hydrazine and compounds of the azide ion. Finally, it led to the name "pnictogens" for the group headed by nitrogen, from the Greek πνίγειν "to choke".


title: Nitrogen

text: The English word nitrogen (1794) entered the language from the French "nitrogène", coined in 1790 by French chemist Jean-Antoine Chaptal (1756–1832), from the French "nitre" (potassium nitrate, also called saltpeter) and the French suffix "-gène", "producing", from the Greek -γενής (-genes, "begotten"). Chaptal's meaning was that nitrogen is the essential part of nitric acid, which in turn was produced from nitre. In earlier times, niter had been confused with Egyptian "natron" (sodium carbonate) – called νίτρον (nitron) in Greek – which, despite the name, contained no nitrate.


title: Nitrogen

text: The earliest military, industrial, and agricultural applications of nitrogen compounds used saltpeter (sodium nitrate or potassium nitrate), most notably in gunpowder, and later as fertiliser. In 1910, Lord Rayleigh discovered that an electrical discharge in nitrogen gas produced "active nitrogen", a monatomic allotrope of nitrogen. The "whirling cloud of brilliant yellow light" produced by his apparatus reacted with mercury to produce explosive mercury nitride.


title: Nitrogen

text: For a long time, sources of nitrogen compounds were limited. Natural sources originated either from biology or deposits of nitrates produced by atmospheric reactions. Nitrogen fixation by industrial processes like the Frank–Caro process (1895–1899) and Haber–Bosch process (1908–1913) eased this shortage of nitrogen compounds, to the extent that half of global food production (see Applications) now relies on synthetic nitrogen fertilisers. At the same time, use of the Ostwald process (1902) to produce nitrates from industrial nitrogen fixation allowed the large-scale industrial production of nitrates as feedstock in the manufacture of explosives in the World Wars of the 20th century.


title: Nitrogen

text: A nitrogen atom has seven electrons. In the ground state, they are arranged in the electron configuration 1s2s2p2p2p. It, therefore, has five valence electrons in the 2s and 2p orbitals, three of which (the p-electrons) are unpaired. It has one of the highest electronegativities among the elements (3.04 on the Pauling scale), exceeded only by chlorine (3.16), oxygen (3.44), and fluorine (3.98). (The light noble gases, helium, neon, and argon, would presumably also be more electronegative, and in fact are on the Allen scale.) Following periodic trends, its single-bond covalent radius of 71 pm is smaller than those of boron (84 pm) and carbon (76 pm), while it is larger than those of oxygen (66 pm) and fluorine (57 pm). The nitride anion, N, is much larger at 146 pm, similar to that of the oxide (O: 140 pm) and fluoride (F: 133 pm) anions. The first three ionisation energies of nitrogen are 1.402, 2.856, and 4.577 MJ·mol, and the sum of the fourth and fifth is . Due to these very high figures, nitrogen has no simple cationic chemistry.


title: Nitrogen

text: The lack of radial nodes in the 2p subshell is directly responsible for many of the anomalous properties of the first row of the p-block, especially in nitrogen, oxygen, and fluorine. The 2p subshell is very small and has a very similar radius to the 2s shell, facilitating orbital hybridisation. It also results in very large electrostatic forces of attraction between the nucleus and the valence electrons in the 2s and 2p shells, resulting in very high electronegativities. Hypervalency is almost unknown in the 2p elements for the same reason, because the high electronegativity makes it difficult for a small nitrogen atom to be a central atom in an electron-rich three-center four-electron bond since it would tend to attract the electrons strongly to itself. Thus, despite nitrogen's position at the head of group 15 in the periodic table, its chemistry shows huge differences from that of its heavier congeners phosphorus, arsenic, antimony, and bismuth.


title: Nitrogen

text: Nitrogen may be usefully compared to its horizontal neighbours' carbon and oxygen as well as its vertical neighbours in the pnictogen column, phosphorus, arsenic, antimony, and bismuth. Although each period 2 element from lithium to oxygen shows some similarities to the period 3 element in the next group (from magnesium to chlorine; these are known as diagonal relationships), their degree drops off abruptly past the boron–silicon pair. The similarities of nitrogen to sulfur are mostly limited to sulfur nitride ring compounds when both elements are the only ones present.


title: Nitrogen

text: Nitrogen does not share the proclivity of carbon for catenation. Like carbon, nitrogen tends to form ionic or metallic compounds with metals. Nitrogen forms an extensive series of nitrides with carbon, including those with chain-, graphitic-, and fullerenic-like structures.


title: Nitrogen

text: It resembles oxygen with its high electronegativity and concomitant capability for hydrogen bonding and the ability to form coordination complexes by donating its lone pairs of electrons. There are some parallels between the chemistry of ammonia NH and water HO. For example, the capacity of both compounds to be protonated to give NH and HO or deprotonated to give NH and OH, with all of these able to be isolated in solid compounds.


title: Nitrogen

text: Nitrogen shares with both its horizontal neighbours a preference for forming multiple bonds, typically with carbon, oxygen, or other nitrogen atoms, through p–p interactions. Thus, for example, nitrogen occurs as diatomic molecules and therefore has very much lower melting (−210 °C) and boiling points (−196 °C) than the rest of its group, as the N molecules are only held together by weak van der Waals interactions and there are very few electrons available to create significant instantaneous dipoles. This is not possible for its vertical neighbours; thus, the nitrogen oxides, nitrites, nitrates, nitro-, nitroso-, azo-, and diazo-compounds, azides, cyanates, thiocyanates, and imino-derivatives find no echo with phosphorus, arsenic, antimony, or bismuth. By the same token, however, the complexity of the phosphorus oxoacids finds no echo with nitrogen. Setting aside their differences, nitrogen and phosphorus form an extensive series of compounds with one another; these have chain, ring, and cage structures.


title: Nitrogen

text: Nitrogen has two stable isotopes: N and N. The first is much more common, making up 99.634% of natural nitrogen, and the second (which is slightly heavier) makes up the remaining 0.366%. This leads to an atomic weight of around 14.007 u. Both of these stable isotopes are produced in the CNO cycle in stars, but N is more common as its neutron capture is the rate-limiting step. N is one of the five stable odd–odd nuclides (a nuclide having an odd number of protons and neutrons); the other four are H, Li, B, and Ta.


title: Nitrogen

text: The relative abundance of N and N is practically constant in the atmosphere but can vary elsewhere, due to natural isotopic fractionation from biological redox reactions and the evaporation of natural ammonia or nitric acid. Biologically mediated reactions (e.g., assimilation, nitrification, and denitrification) strongly control nitrogen dynamics in the soil. These reactions typically result in N enrichment of the substrate and depletion of the product.


title: Nitrogen

text: The heavy isotope N was first discovered by S. M. Naudé in 1929, and soon after heavy isotopes of the neighbouring elements oxygen and carbon were discovered. It presents one of the lowest thermal neutron capture cross-sections of all isotopes. It is frequently used in nuclear magnetic resonance (NMR) spectroscopy to determine the structures of nitrogen-containing molecules, due to its fractional nuclear spin of one-half, which offers advantages for NMR such as narrower line width. N, though also theoretically usable, has an integer nuclear spin of one and thus has a quadrupole moment that leads to wider and less useful spectra. N NMR nevertheless has complications not encountered in the more common H and C NMR spectroscopy. The low natural abundance of N (0.36%) significantly reduces sensitivity, a problem which is only exacerbated by its low gyromagnetic ratio, (only 10.14% that of H). As a result, the signal-to-noise ratio for H is about 300 times as much as that for N at the same magnetic field strength. This may be somewhat alleviated by isotopic enrichment of N by chemical exchange or fractional distillation. N-enriched compounds have the advantage that under standard conditions, they do not undergo chemical exchange of their nitrogen atoms with atmospheric nitrogen, unlike compounds with labelled hydrogen, carbon, and oxygen isotopes that must be kept away from the atmosphere. The N:N ratio is commonly used in stable isotope analysis in the fields of geochemistry, hydrology, paleoclimatology and paleoceanography, where it is called "δ"N.


title: Nitrogen

text: Of the ten other isotopes produced synthetically, ranging from N to N, N has a half-life of ten minutes and the remaining isotopes have half-lives on the order of seconds (N and N) or milliseconds. No other nitrogen isotopes are possible as they would fall outside the nuclear drip lines, leaking out a proton or neutron. Given the half-life difference, N is the most important nitrogen radioisotope, being relatively long-lived enough to use in positron emission tomography (PET), although its half-life is still short and thus it must be produced at the venue of the PET, for example in a cyclotron via proton bombardment of O producing N and an alpha particle.


title: Nitrogen

text: The radioisotope N is the dominant radionuclide in the coolant of pressurised water reactors or boiling water reactors during normal operation. It is produced from O (in water) via an (n,p) reaction, in which the O atom captures a neutron and expels a proton. It has a short half-life of about 7.1 s, but during its decay back to O produces high-energy gamma radiation (5 to 7 MeV). Because of this, access to the primary coolant piping in a pressurised water reactor must be restricted during reactor power operation. It is a sensitive and immediate indicator of leaks from the primary coolant system to the secondary steam cycle and is the primary means of detection for such leaks.


title: Nitrogen

text: Atomic nitrogen, also known as active nitrogen, is highly reactive, being a triradical with three unpaired electrons. Free nitrogen atoms easily react with most elements to form nitrides, and even when two free nitrogen atoms collide to produce an excited N molecule, they may release so much energy on collision with even such stable molecules as carbon dioxide and water to cause homolytic fission into radicals such as CO and O or OH and H. Atomic nitrogen is prepared by passing an electric discharge through nitrogen gas at 0.1–2 mmHg, which produces atomic nitrogen along with a peach-yellow emission that fades slowly as an afterglow for several minutes even after the discharge terminates.


title: Nitrogen

text: Given the great reactivity of atomic nitrogen, elemental nitrogen usually occurs as molecular N, dinitrogen. This molecule is a colourless, odourless, and tasteless diamagnetic gas at standard conditions: it melts at −210 °C and boils at −196 °C. Dinitrogen is mostly unreactive at room temperature, but it will nevertheless react with lithium metal and some transition metal complexes. This is due to its bonding, which is unique among the diatomic elements at standard conditions in that it has an N≡N triple bond. Triple bonds have short bond lengths (in this case, 109.76 pm) and high dissociation energies (in this case, 945.41 kJ/mol), and are thus very strong, explaining dinitrogen's low level of chemical reactivity.


title: Nitrogen

text: Other nitrogen oligomers and polymers may be possible. If they could be synthesised, they may have potential applications as materials with a very high energy density, that could be used as powerful propellants or explosives. Under extremely high pressures (1.1 million atm) and high temperatures (2000 K), as produced in a diamond anvil cell, nitrogen polymerises into the single-bonded cubic gauche crystal structure. This structure is similar to that of diamond, and both have extremely strong covalent bonds, resulting in its nickname "nitrogen diamond".


title: Nitrogen

text: At atmospheric pressure, molecular nitrogen condenses (liquefies) at 77 K (−195.79 °C) and freezes at 63 K (−210.01 °C) into the beta hexagonal close-packed crystal allotropic form. Below 35.4 K (−237.6 °C) nitrogen assumes the cubic crystal allotropic form (called the alpha phase). Liquid nitrogen, a colourless fluid resembling water in appearance, but with 80.8% of the density (the density of liquid nitrogen at its boiling point is 0.808 g/mL), is a common cryogen. Solid nitrogen has many crystalline modifications. It forms a significant dynamic surface coverage on Pluto and outer moons of the Solar System such as Triton. Even at the low temperatures of solid nitrogen it is fairly volatile and can sublime to form an atmosphere, or condense back into nitrogen frost. It is very weak and flows in the form of glaciers and on Triton geysers of nitrogen gas come from the polar ice cap region.


title: Nitrogen

text: The first example of a dinitrogen complex to be discovered was [Ru(NH)(N)] (see figure at right), and soon many other such complexes were discovered. These complexes, in which a nitrogen molecule donates at least one lone pair of electrons to a central metal cation, illustrate how N might bind to the metal(s) in nitrogenase and the catalyst for the Haber process: these processes involving dinitrogen activation are vitally important in biology and in the production of fertilisers.


title: Nitrogen

text: Dinitrogen is able to coordinate to metals in five different ways. The more well-characterised ways are the end-on M←N≡N ("η") and M←N≡N→M ("μ", bis-"η"), in which the lone pairs on the nitrogen atoms are donated to the metal cation. The less well-characterised ways involve dinitrogen donating electron pairs from the triple bond, either as a bridging ligand to two metal cations ("μ", bis-"η") or to just one ("η"). The fifth and unique method involves triple-coordination as a bridging ligand, donating all three electron pairs from the triple bond ("μ"-N). A few complexes feature multiple N ligands and some feature N bonded in multiple ways. Since N is isoelectronic with carbon monoxide (CO) and acetylene (CH), the bonding in dinitrogen complexes is closely allied to that in carbonyl compounds, although N is a weaker "σ"-donor and "π"-acceptor than CO. Theoretical studies show that "σ" donation is a more important factor allowing the formation of the M–N bond than "π" back-donation, which mostly only weakens the N–N bond, and end-on ("η") donation is more readily accomplished than side-on ("η") donation.


title: Nitrogen

text: Today, dinitrogen complexes are known for almost all the transition metals, accounting for several hundred compounds. They are normally prepared by three methods:


title: Nitrogen

text: Occasionally the N≡N bond may be formed directly within a metal complex, for example by directly reacting coordinated ammonia (NH) with nitrous acid (HNO), but this is not generally applicable. Most dinitrogen complexes have colours within the range white-yellow-orange-red-brown; a few exceptions are known, such as the blue [{Ti("η"-CH)}-(N)].


title: Nitrogen

text: Nitrogen bonds to almost all the elements in the periodic table except the first three noble gases, helium, neon, and argon, and some of the very short-lived elements after bismuth, creating an immense variety of binary compounds with varying properties and applications in which pentazenium tetraazidoborate has the highest nitrogen content. Many binary compounds are known: with the exception of the nitrogen hydrides, oxides, and fluorides, these are typically called nitrides. Many stoichiometric phases are usually present for most elements (e.g. MnN, MnN, MnN, MnN, MnN, and MnN for 9.2 < "x" < 25.3). They may be classified as "salt-like" (mostly ionic), covalent, "diamond-like", and metallic (or interstitial), although this classification has limitations generally stemming from the continuity of bonding types instead of the discrete and separate types that it implies. They are normally prepared by directly reacting a metal with nitrogen or ammonia (sometimes after heating), or by thermal decomposition of metal amides:


title: Nitrogen

text: Many variants on these processes are possible. The most ionic of these nitrides are those of the alkali metals and alkaline earth metals, LiN (Na, K, Rb, and Cs do not form stable nitrides for steric reasons) and MN (M = Be, Mg, Ca, Sr, Ba). These can formally be thought of as salts of the N anion, although charge separation is not actually complete even for these highly electropositive elements. However, the alkali metal azides NaN and KN, featuring the linear anion, are well-known, as are Sr(N) and Ba(N). Azides of the B-subgroup metals (those in groups 11 through 16) are much less ionic, have more complicated structures, and detonate readily when shocked.


title: Nitrogen

text: Many covalent binary nitrides are known. Examples include cyanogen ((CN)), triphosphorus pentanitride (PN), disulfur dinitride (SN), and tetrasulfur tetranitride (SN). The essentially covalent silicon nitride (SiN) and germanium nitride (GeN) are also known: silicon nitride, in particular, would make a promising ceramic if not for the difficulty of working with and sintering it. In particular, the group 13 nitrides, most of which are promising semiconductors, are isoelectronic with graphite, diamond, and silicon carbide and have similar structures: their bonding changes from covalent to partially ionic to metallic as the group is descended. In particular, since the B–N unit is isoelectronic to C–C, and carbon is essentially intermediate in size between boron and nitrogen, much of organic chemistry finds an echo in boron–nitrogen chemistry, such as in borazine ("inorganic benzene"). Nevertheless, the analogy is not exact due to the ease of nucleophilic attack at boron due to its deficiency in electrons, which is not possible in a wholly carbon-containing ring.


title: Nitrogen

text: The largest category of nitrides are the interstitial nitrides of formulae MN, MN, and MN (although variable composition is perfectly possible), where the small nitrogen atoms are positioned in the gaps in a metallic cubic or hexagonal close-packed lattice. They are opaque, very hard, and chemically inert, melting only at very high temperatures (generally over 2500 °C). They have a metallic lustre and conduct electricity as do metals. They hydrolyse only very slowly to give ammonia or nitrogen.


title: Nitrogen

text: The nitride anion (N) is the strongest "π" donor known among ligands (the second-strongest is O). Nitrido complexes are generally made by the thermal decomposition of azides or by deprotonating ammonia, and they usually involve a terminal {≡N} group. The linear azide anion (), being isoelectronic with nitrous oxide, carbon dioxide, and cyanate, forms many coordination complexes. Further catenation is rare, although (isoelectronic with carbonate and nitrate) is known.


title: Nitrogen

text: Industrially, ammonia (NH) is the most important compound of nitrogen and is prepared in larger amounts than any other compound because it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilisers. It is a colourless alkaline gas with a characteristic pungent smell. The presence of hydrogen bonding has very significant effects on ammonia, conferring on it its high melting (−78 °C) and boiling (−33 °C) points. As a liquid, it is a very good solvent with a high heat of vaporisation (enabling it to be used in vacuum flasks), that also has a low viscosity and electrical conductivity and high dielectric constant, and is less dense than water. However, the hydrogen bonding in NH is weaker than that in HO due to the lower electronegativity of nitrogen compared to oxygen and the presence of only one lone pair in NH rather than two in HO. It is a weak base in aqueous solution (p"K" 4.74); its conjugate acid is ammonium, . It can also act as an extremely weak acid, losing a proton to produce the amide anion, . It thus undergoes self-dissociation, similar to water, to produce ammonium and amide. Ammonia burns in air or oxygen, though not readily, to produce nitrogen gas; it burns in fluorine with a greenish-yellow flame to give nitrogen trifluoride. Reactions with the other nonmetals are very complex and tend to lead to a mixture of products. Ammonia reacts on heating with metals to give nitrides.


title: Nitrogen

text: Many other binary nitrogen hydrides are known, but the most important are hydrazine (NH) and hydrogen azide (HN). Although it is not a nitrogen hydride, hydroxylamine (NHOH) is similar in properties and structure to ammonia and hydrazine as well. Hydrazine is a fuming, colourless liquid that smells similar to ammonia. Its physical properties are very similar to those of water (melting point 2.0 °C, boiling point 113.5 °C, density 1.00 g/cm). Despite it being an endothermic compound, it is kinetically stable. It burns quickly and completely in air very exothermically to give nitrogen and water vapour. It is a very useful and versatile reducing agent and is a weaker base than ammonia. It is also commonly used as a rocket fuel.


title: Nitrogen

text: Hydrazine is generally made by reaction of ammonia with alkaline sodium hypochlorite in the presence of gelatin or glue:


title: Nitrogen

text: (The attacks by hydroxide and ammonia may be reversed, thus passing through the intermediate NHCl instead.) The reason for adding gelatin is that it removes metal ions such as Cu that catalyses the destruction of hydrazine by reaction with monochloramine (NHCl) to produce ammonium chloride and nitrogen.


title: Nitrogen

text: Hydrogen azide (HN) was first produced in 1890 by the oxidation of aqueous hydrazine by nitrous acid. It is very explosive and even dilute solutions can be dangerous. It has a disagreeable and irritating smell and is a potentially lethal (but not cumulative) poison. It may be considered the conjugate acid of the azide anion, and is similarly analogous to the hydrohalic acids.


title: Nitrogen

text: All four simple nitrogen trihalides are known. A few mixed halides and hydrohalides are known, but are mostly unstable; examples include NClF, NClF, NBrF, NFH, NFH, NClH, and NClH.


title: Nitrogen

text: Five nitrogen fluorides are known. Nitrogen trifluoride (NF, first prepared in 1928) is a colourless and odourless gas that is thermodynamically stable, and most readily produced by the electrolysis of molten ammonium fluoride dissolved in anhydrous hydrogen fluoride. Like carbon tetrafluoride, it is not at all reactive and is stable in water or dilute aqueous acids or alkalis. Only when heated does it act as a fluorinating agent, and it reacts with copper, arsenic, antimony, and bismuth on contact at high temperatures to give tetrafluorohydrazine (NF). The cations and are also known (the latter from reacting tetrafluorohydrazine with strong fluoride-acceptors such as arsenic pentafluoride), as is ONF, which has aroused interest due to the short N–O distance implying partial double bonding and the highly polar and long N–F bond. Tetrafluorohydrazine, unlike hydrazine itself, can dissociate at room temperature and above to give the radical NF•. Fluorine azide (FN) is very explosive and thermally unstable. Dinitrogen difluoride (NF) exists as thermally interconvertible "cis" and "trans" isomers, and was first found as a product of the thermal decomposition of FN.


title: Nitrogen

text: Nitrogen trichloride (NCl) is a dense, volatile, and explosive liquid whose physical properties are similar to those of carbon tetrachloride, although one difference is that NCl is easily hydrolysed by water while CCl is not. It was first synthesised in 1811 by Pierre Louis Dulong, who lost three fingers and an eye to its explosive tendencies. As a dilute gas it is less dangerous and is thus used industrially to bleach and sterilise flour. Nitrogen tribromide (NBr), first prepared in 1975, is a deep red, temperature-sensitive, volatile solid that is explosive even at −100 °C. Nitrogen triiodide (NI) is still more unstable and was only prepared in 1990. Its adduct with ammonia, which was known earlier, is very shock-sensitive: it can be set off by the touch of a feather, shifting air currents, or even alpha particles. For this reason, small amounts of nitrogen triiodide are sometimes synthesised as a demonstration to high school chemistry students or as an act of "chemical magic". Chlorine azide (ClN) and bromine azide (BrN) are extremely sensitive and explosive.


title: Nitrogen

text: Two series of nitrogen oxohalides are known: the nitrosyl halides (XNO) and the nitryl halides (XNO). The first is very reactive gases that can be made by directly halogenating nitrous oxide. Nitrosyl fluoride (NOF) is colourless and a vigorous fluorinating agent. Nitrosyl chloride (NOCl) behaves in much the same way and has often been used as an ionising solvent. Nitrosyl bromide (NOBr) is red. The reactions of the nitryl halides are mostly similar: nitryl fluoride (FNO) and nitryl chloride (ClNO) are likewise reactive gases and vigorous halogenating agents.


title: Nitrogen

text: Nitrogen forms nine molecular oxides, some of which were the first gases to be identified: NO (nitrous oxide), NO (nitric oxide), NO (dinitrogen trioxide), NO (nitrogen dioxide), NO (dinitrogen tetroxide), NO (dinitrogen pentoxide), NO (nitrosylazide), and N(NO) (trinitramide). All are thermally unstable towards decomposition to their elements. One other possible oxide that has not yet been synthesised is oxatetrazole (NO), an aromatic ring.


title: Nitrogen

text: Nitrous oxide (NO), better known as laughing gas, is made by thermal decomposition of molten ammonium nitrate at 250 °C. This is a redox reaction and thus nitric oxide and nitrogen are also produced as byproducts. It is mostly used as a propellant and aerating agent for sprayed canned whipped cream, and was formerly commonly used as an anaesthetic. Despite appearances, it cannot be considered to be the anhydride of hyponitrous acid (HNO) because that acid is not produced by the dissolution of nitrous oxide in water. It is rather unreactive (not reacting with the halogens, the alkali metals, or ozone at room temperature, although reactivity increases upon heating) and has the unsymmetrical structure N–N–O (N≡NO↔N=N=O): above 600 °C it dissociates by breaking the weaker N–O bond.


title: Nitrogen

text: Nitric oxide (NO) is the simplest stable molecule with an odd number of electrons. In mammals, including humans, it is an important cellular signaling molecule involved in many physiological and pathological processes. It is formed by catalytic oxidation of ammonia. It is a colourless paramagnetic gas that, being thermodynamically unstable, decomposes to nitrogen and oxygen gas at 1100–1200 °C. Its bonding is similar to that in nitrogen, but one extra electron is added to a "π"* antibonding orbital and thus the bond order has been reduced to approximately 2.5; hence dimerisation to O=N–N=O is unfavourable except below the boiling point (where the "cis" isomer is more stable) because it does not actually increase the total bond order and because the unpaired electron is delocalised across the NO molecule, granting it stability. There is also evidence for the asymmetric red dimer O=N–O=N when nitric oxide is condensed with polar molecules. It reacts with oxygen to give brown nitrogen dioxide and with halogens to give nitrosyl halides. It also reacts with transition metal compounds to give nitrosyl complexes, most of which are deeply coloured.


title: Nitrogen

text: Blue dinitrogen trioxide (NO) is only available as a solid because it rapidly dissociates above its melting point to give nitric oxide, nitrogen dioxide (NO), and dinitrogen tetroxide (NO). The latter two compounds are somewhat difficult to study individually because of the equilibrium between them, although sometimes dinitrogen tetroxide can react by heterolytic fission to nitrosonium and nitrate in a medium with high dielectric constant. Nitrogen dioxide is an acrid, corrosive brown gas. Both compounds may be easily prepared by decomposing a dry metal nitrate. Both react with water to form nitric acid. Dinitrogen tetroxide is very useful for the preparation of anhydrous metal nitrates and nitrato complexes, and it became the storable oxidiser of choice for many rockets in both the United States and USSR by the late 1950s. This is because it is a hypergolic propellant in combination with a hydrazine-based rocket fuel and can be easily stored since it is liquid at room temperature.


title: Nitrogen

text: The thermally unstable and very reactive dinitrogen pentoxide (NO) is the anhydride of nitric acid, and can be made from it by dehydration with phosphorus pentoxide. It is of interest for the preparation of explosives. It is a deliquescent, colourless crystalline solid that is sensitive to light. In the solid state it is ionic with structure [NO][NO]; as a gas and in solution it is molecular ON–O–NO. Hydration to nitric acid comes readily, as does analogous reaction with hydrogen peroxide giving peroxonitric acid (HOONO). It is a violent oxidising agent. Gaseous dinitrogen pentoxide decomposes as follows:


title: Nitrogen

text: Many nitrogen oxoacids are known, though most of them are unstable as pure compounds and are known only as aqueous solutions or as salts. Hyponitrous acid (HNO) is a weak diprotic acid with the structure HON=NOH (p"K" 6.9, p"K" 11.6). Acidic solutions are quite stable but above pH 4 base-catalysed decomposition occurs via [HONNO] to nitrous oxide and the hydroxide anion. Hyponitrites (involving the anion) are stable to reducing agents and more commonly act as reducing agents themselves. They are an intermediate step in the oxidation of ammonia to nitrite, which occurs in the nitrogen cycle. Hyponitrite can act as a bridging or chelating bidentate ligand.


title: Nitrogen

text: Nitrous acid (HNO) is not known as a pure compound, but is a common component in gaseous equilibria and is an important aqueous reagent: its aqueous solutions may be made from acidifying cool aqueous nitrite (, bent) solutions, although already at room temperature disproportionation to nitrate and nitric oxide is significant. It is a weak acid with p"K" 3.35 at 18 °C. They may be titrimetrically analysed by their oxidation to nitrate by permanganate. They are readily reduced to nitrous oxide and nitric oxide by sulfur dioxide, to hyponitrous acid with tin(II), and to ammonia with hydrogen sulfide. Salts of hydrazinium react with nitrous acid to produce azides which further react to give nitrous oxide and nitrogen. Sodium nitrite is mildly toxic in concentrations above 100 mg/kg, but small amounts are often used to cure meat and as a preservative to avoid bacterial spoilage. It is also used to synthesise hydroxylamine and to diazotise primary aromatic amines as follows:


title: Nitrogen

text: Nitrite is also a common ligand that can coordinate in five ways. The most common are nitro (bonded from the nitrogen) and nitrito (bonded from an oxygen). Nitro-nitrito isomerism is common, where the nitrito form is usually less stable.


title: Nitrogen

text: Nitric acid (HNO) is by far the most important and the most stable of the nitrogen oxoacids. It is one of the three most used acids (the other two being sulfuric acid and hydrochloric acid) and was first discovered by alchemists in the 13th century. It is made by the catalytic oxidation of ammonia to nitric oxide, which is oxidised to nitrogen dioxide, and then dissolved in water to give concentrated nitric acid. In the United States of America, over seven million tonnes of nitric acid are produced every year, most of which is used for nitrate production for fertilisers and explosives, among other uses. Anhydrous nitric acid may be made by distilling concentrated nitric acid with phosphorus pentoxide at low pressure in glass apparatus in the dark. It can only be made in the solid state, because upon melting it spontaneously decomposes to nitrogen dioxide, and liquid nitric acid undergoes self-ionisation to a larger extent than any other covalent liquid as follows:


title: Nitrogen

text: Two hydrates, HNO·HO and HNO·3HO, are known that can be crystallised. It is a strong acid and concentrated solutions are strong oxidising agents, though gold, platinum, rhodium, and iridium are immune to attack. A 3:1 mixture of concentrated hydrochloric acid and nitric acid, called "aqua regia", is still stronger and successfully dissolves gold and platinum, because free chlorine and nitrosyl chloride are formed and chloride anions can form strong complexes. In concentrated sulfuric acid, nitric acid is protonated to form nitronium, which can act as an electrophile for aromatic nitration:


title: Nitrogen

text: The thermal stabilities of nitrates (involving the trigonal planar anion) depends on the basicity of the metal, and so do the products of decomposition (thermolysis), which can vary between the nitrite (for example, sodium), the oxide (potassium and lead), or even the metal itself (silver) depending on their relative stabilities. Nitrate is also a common ligand with many modes of coordination.


title: Nitrogen

text: Finally, although orthonitric acid (HNO), which would be analogous to orthophosphoric acid, does not exist, the tetrahedral orthonitrate anion is known in its sodium and potassium salts:


title: Nitrogen

text: Despite its limited chemistry, the orthonitrate anion is interesting from a structural point of view due to its regular tetrahedral shape and the short N–O bond lengths, implying significant polar character to the bonding.


title: Nitrogen

text: Nitrogen is one of the most important elements in organic chemistry. Many organic functional groups involve a carbon–nitrogen bond, such as amides (RCONR), amines (RN), imines (RC(=NR)R), imides (RCO)NR, azides (RN), azo compounds (RNR), cyanates and isocyanates (ROCN or RCNO), nitrates (RONO), nitriles and isonitriles (RCN or RNC), nitrites (RONO), nitro compounds (RNO), nitroso compounds (RNO), oximes (RCR=NOH), and pyridine derivatives. C–N bonds are strongly polarised towards nitrogen. In these compounds, nitrogen is usually trivalent (though it can be tetravalent in quaternary ammonium salts, RN), with a lone pair that can confer basicity on the compound by being coordinated to a proton. This may be offset by other factors: for example, amides are not basic because the lone pair is delocalised into a double bond (though they may act as acids at very low pH, being protonated at the oxygen), and pyrrole is not acidic because the lone pair is delocalised as part of an aromatic ring. The amount of nitrogen in a chemical substance can be determined by the Kjeldahl method. In particular, nitrogen is an essential component of nucleic acids, amino acids and thus proteins, and the energy-carrying molecule adenosine triphosphate and is thus vital to all life on Earth.


title: Nitrogen

text: Nitrogen is the most common pure element in the earth, making up 78.1% of the volume of the atmosphere (75.5% by mass), around 3.89 million gigatonnes. Despite this, it is not very abundant in Earth's crust, making up somewhere around 19 parts per million of this, on par with niobium, gallium, and lithium. (This represents 300,000 to a million gigatonnes of nitrogen, depending on the mass of the crust.) The only important nitrogen minerals are nitre (potassium nitrate, saltpetre) and soda nitre (sodium nitrate, Chilean saltpetre). However, these have not been an important source of nitrates since the 1920s, when the industrial synthesis of ammonia and nitric acid became common.


title: Nitrogen

text: Nitrogen compounds constantly interchange between the atmosphere and living organisms. Nitrogen must first be processed, or "fixed", into a plant-usable form, usually ammonia. Some nitrogen fixation is done by lightning strikes producing the nitrogen oxides, but most is done by diazotrophic bacteria through enzymes known as nitrogenases (although today industrial nitrogen fixation to ammonia is also significant). When the ammonia is taken up by plants, it is used to synthesise proteins. These plants are then digested by animals who use the nitrogen compounds to synthesise their proteins and excrete nitrogen-bearing waste. Finally, these organisms die and decompose, undergoing bacterial and environmental oxidation and denitrification, returning free dinitrogen to the atmosphere. Industrial nitrogen fixation by the Haber process is mostly used as fertiliser, although excess nitrogen–bearing waste, when leached, leads to eutrophication of freshwater and the creation of marine dead zones, as nitrogen-driven bacterial growth depletes water oxygen to the point that all higher organisms die. Furthermore, nitrous oxide, which is produced during denitrification, attacks the atmospheric ozone layer.


title: Nitrogen

text: Many saltwater fish manufacture large amounts of trimethylamine oxide to protect them from the high osmotic effects of their environment; conversion of this compound to dimethylamine is responsible for the early odour in unfresh saltwater fish. In animals, free radical nitric oxide (derived from an amino acid), serves as an important regulatory molecule for circulation.


title: Nitrogen

text: Nitric oxide's rapid reaction with water in animals results in the production of its metabolite nitrite. Animal metabolism of nitrogen in proteins, in general, results in the excretion of urea, while animal metabolism of nucleic acids results in the excretion of urea and uric acid. The characteristic odour of animal flesh decay is caused by the creation of long-chain, nitrogen-containing amines, such as putrescine and cadaverine, which are breakdown products of the amino acids ornithine and lysine, respectively, in decaying proteins.


title: Nitrogen

text: Nitrogen gas is an industrial gas produced by the fractional distillation of liquid air, or by mechanical means using gaseous air (pressurised reverse osmosis membrane or pressure swing adsorption). Nitrogen gas generators using membranes or pressure swing adsorption (PSA) are typically more cost and energy efficient than bulk-delivered nitrogen. Commercial nitrogen is often a byproduct of air-processing for industrial concentration of oxygen for steelmaking and other purposes. When supplied compressed in cylinders it is often called OFN (oxygen-free nitrogen). Commercial-grade nitrogen already contains at most 20 ppm oxygen, and specially purified grades containing at most 2 ppm oxygen and 10 ppm argon are also available.


title: Nitrogen

text: In a chemical laboratory, it is prepared by treating an aqueous solution of ammonium chloride with sodium nitrite.


title: Nitrogen

text: Small amounts of the impurities NO and HNO are also formed in this reaction. The impurities can be removed by passing the gas through aqueous sulfuric acid containing potassium dichromate. Very pure nitrogen can be prepared by the thermal decomposition of barium azide or sodium azide.


title: Nitrogen

text: The applications of nitrogen compounds are naturally extremely widely varied due to the huge size of this class: hence, only applications of pure nitrogen itself will be considered here. Two-thirds (2/3) of nitrogen produced by industry is sold as gas and the remaining one-third (1/3) as a liquid.


title: Nitrogen

text: The gas is mostly used as a low reactivity safe atmosphere wherever the oxygen in the air would pose a fire, explosion, or oxidising hazard. Some examples include:


title: Nitrogen

text: Nitrogen is commonly used during sample preparation in chemical analysis. It is used to concentrate and reduce the volume of liquid samples. Directing a pressurised stream of nitrogen gas perpendicular to the surface of the liquid causes the solvent to evaporate while leaving the solute(s) and un-evaporated solvent behind.