Atomic Number: 51 Period Number: 5 Group Number: 15
Antimony is a silvery-grey and brittle metal. There are few free element of antimony in nature and most of them exist as minerals and ores. One of the largest sources of antimony is China. Two stable isotopes of Antimony exist in nature - 121Sb and 123Sb. Four allotropes of antimony are known, a stable metallic form and three metastable forms, explosive, black and yellow.
Antimony is widely used in batteries, solder, bearings, semiconductors, etc. Around 50% of pure antimony currently produced is used for hardening lead, to make alloys which are then used (mostly) in batteries. However, the hardened alloy also finds use in small arms bullets (and tracer rounds) and cable sheathing among others. Whilst too brittle to be of use in its pure form, antimony makes an excellent alloying material for other metals, providing increased hardness and mechanical strength. And because of its ability of expanding on freezing, antimony also can be used for making high quality type for mechanical printing presses.
Many other antimony compounds find use in the ceramics and glass industries as glazes, paints and pigments, primarily the sulphides, oxides, antimony trichloride and sodium antimonate. Antimony trioxide (SbO3) is a highly effective flame retardant, and has been used for some time in the manufacture of clothing, children's toys, and car/aeroplane seat covers. Hydrated potassium antimonyltartate (KSbC4H4O7·0.5H2O), known also as tartar emetic is used as a mordent in fabric dyeing and medicinally as an emetic and expectorant.
Physical and Chemical properties:
Atomic Weight: 121.760
Melting Point: 903.78 K
Boiling Point: 1860 K
Density: 6.685 g/cm3
Phase at Room Temperature: Solid
Element Classification: Semi-metal
Ionization Energy: 8.64 eV
Oxidation States: +5, +3, -3
Wikipedia - Basics on Antimony
WebElements - The basic elements of Antimony
Jefferson Lab - Learning about Antimony