Antimony is a chemical element with the symbol Sb and atomic number 51. A lustrous gray metalloid is found in nature, mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for medicine and cosmetics, often known by the Arabic name kohl. Metallic antimony was also known, but it was erroneously identified as lead upon its discovery. Antimony is a member of group 15 of the periodic table, one of the elements called pnictogens, and has an electronegativity of 2.05.
A pnictogen is one of the chemical elements in group 15 of the periodic table. This group is also known as the nitrogen family. The chalcogens are the chemical elements in group 16 of the periodic table. This group is also known as the oxygen family.
Pnictogens consist of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and perhaps the chemically uncharacterized synthetic element moscovium (Mc).