Metalloid
Physical property Metals Metalloids Nonmetals
Form solid ; a few liquid at or near room temperature ( Ga , Hg , Rb , Cs , Fr ) solid majority gaseous
Appearance lustrous ( at least when freshly fractured ) lustrous several colourless ; others coloured , or metallic grey to black
Elasticity typically elastic , ductile , malleable ( when solid ) brittle brittle , if solid
Electrical conductivity good to high intermediate to good poor to good
Band structure metallic ( Bi = semimetallic ) are semiconductors or , if not ( As , Sb = semimetallic ) , exist in semiconducting forms semiconductor or insulator
Chemical property Metals Metalloids Nonmetals
General chemical behaviour metallic nonmetallic nonmetallic
Ionization energy relatively low intermediate ionization energies , usually falling between those of metals and nonmetals relatively high
Electronegativity usually low have electronegativity values close to 2 ( revised Pauling scale ) or within the range of 1.9-2.2 ( Allen scale ) high
When mixed with metals give alloys can form alloys ionic or interstitial compounds formed
Oxides lower oxides basic ; higher oxides increasingly acidic amphoteric or weakly acidic acidic
Properties -- Compared to metals and nonmetals
Main article : Properties of metals , metalloids , and nonmetals Characteristic properties of metals , metalloids , and nonmetals are summarized in the table . [ 84 ] Physical properties are listed in order of ease of determination ; chemical properties run from general to specific , and then to descriptive .
A metalloid is a type of chemical element which has properties in between, or that are a mixture of, those of metals and nonmetals. There is neither a standard definition of a metalloid nor complete agreement on the elements appropriately classified as such. Despite the lack of specificity, the term remains in use in the literature of chemistry. The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium. Five elements are less frequently so classified: carbon, aluminium, selenium, polonium, and astatine. On a standard periodic table, all eleven elements are located in a diagonal region of the p-block extending from boron at the upper left to astatine at lower right. Some periodic tables include a dividing line between metals and nonmetals and the metalloids may be found close to this line. Typical metalloids have a metallic appearance, but they are brittle and only fair conductors of electricity. Chemically, they behave mostly as nonmetals. They can form alloys with metals. Most of their other physical properties and chemical properties are intermediate in nature. Metalloids are usually too brittle to have any structural uses.