antimony (Sb)


Antimony. Credit: Aram Dulyan & Wikipedia

Antimony (Sb) is a brittle, toxic, semimetallic element (see metalloid), which expands on solidifying; it lies in group VA of the periodic table. It occurs as the element, oxide, and, most commonly, sulfide (stibnite, Sb2S3); from stibnite it is extracted roasting the ore to give antimony (II) oxide and then reducing this with carbon.


Antimony is used in type metal and other alloys, particularly in hardening lead for batteries, and in semiconductors. It has two allotropes: a silvery white metallic form and an amorphous gray form. Its most common isotope is 121Sb (57.25%).


Although rather unreactive, antimony forms trivalent and pentavalent oxides, halides, and oxyanions. Certain antimony compounds are used in the manufacture of medicines, paints, matches, explosives, and fireproofing materials.


atomic number 51
relative atomic mass 121.75
relative density 6.68
melting point 630.5°C (1,166.9°F)
boiling point 1,750°C (3,182°F)