Page 20 - Curriculum Visions Dynamic Book

Antimony (Sb)
Element 51. Antimony, a metalloid in group 5 (the nitrogen group) in the Periodic Table, gets its symbol from the Latin for tin, stibium.
It is a silvery, bluish-white solid, which is very brittle and has a flaky texture.
It is found as a grey sulphide mineral called stibnite.Antimony
is a poor conductor of heat and electricity, and tarnishes only slightly in air, more in moist air. When it is heated in air, it burns with a brilliant blue flame and gives out white fumes. It has no uses as
a pure element; but when alloyed with metals, it makes the alloy hard and strong.
Discovery
Antimony has been known since ancient
Technology
Antimony is obtained by heating the sulphide with iron.The sulphide reacts with the iron to leave the element antimony. The earliest use of antimony was as black eye make-up. It is now used as a doping compound in semi-conductors and as an alloy to harden lead. In this way it appears in bullets and armour for electrical cables. The alloy also has low friction qualities. Many compounds are used in flame- proofing and in paints, glass and ceramics.
Geology
Native antimony is occasionally found. However, most antimony occurs in the mineral form.The main minerals of antimony are the sulphides stibnite (Sb2S3) and ullmanite (NiSbS).
Biology
Antimony and its compounds are toxic, causing liver damage.They are also an irritant to the skin. In the past antimony compounds have been used as medicines, but their highly poisonous character means they were of dubious value.
Key facts...
Name: antimony
Symbol: Sb
Atomic number: 51
Atomic weight: 121.75
Position in Periodic Table: group 5 (15) (nitrogen
group); period 5
State at room temperature: solid
Colour: bluish-white
Density of solid: 6.69 g/cc
Melting point: 630°C
Boiling point: 1,380°C
Origin of name: from the Greek words anti +
monos, meaning not alone. The symbol Sb
comes from the Latin word stibium, meaning tin. Shell pattern of electrons: 2–8–18–18–5
times.
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