Another member of this group is commonly used in medical testing because it doesn't harm the parathyroid.
Separation of one member of this group from its synthetic source requires a quartz vessel and collection with weak nitric acid. An acid of one of these compounds with antimony provides the basis for the Gutmann donor number. Members of this group are good sigma and pi electron donors, and form X-type ligands. Alkali compounds of this group have octahedral geometry, while the first discovered xenon compounds contained elements of this group. Aluminum or iron compounds with one of these elements can be used as (*) Friedel-Crafts reagents, and alkyl compounds with a member of this group readily react in nucleophilic substitution reactions. Another member of this group is commonly used in medical testing because it doesn't harm the parathyroid. For 10 points, name these members of group 17 of the periodic table, which includes the most electronegative element, flourine.
Separation of one member of this group from its synthetic source requires a quartz vessel and collection with weak nitric acid.
halogens (or group 17 before mention)