Antimony (Sb)
“Pharaohs ground its black ore into kohl eyeliner five thousand years ago; today it hardens the battery plates that start our engines.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
Characteristics
- A textbook metalloid — semiconducting yet lustrous — with configuration [Kr] 4d¹⁰ 5s² 5p³ in Group 15 (the nitrogen family), Period 5, p-block.
- Like water, it expands slightly on solidifying — a rare metal trick that once filled printers’ moulds edge-to-edge with razor-sharp type.
- Much like its neighbour arsenic, its compounds are toxic in excess; the metal shows chiefly +3 and +5 oxidation states, as in Sb₂O₃ and Sb₂S₃.
- Its oxide Sb₂O₃ teams up with brominated compounds to choke flames, making antimony a quiet partner in flame retardants.
A brittle, crystalline, silvery-white metalloid whose flakes glitter like a hall of mirrors when struck. It looks convincingly metallic yet shatters like china — the split personality that defines a metalloid.
Where you meet it
✦ Uses
- Hardening the lead plates of lead-acid batteries — the workhorses that crank engines, run Bangladeshi home IPS units during load-shedding and power easy-bikes.
- Antimony trioxide (Sb₂O₃) as a flame-retardant helper in TV cabinets, mattress foam and electrical plastics.
- The catalyst that polymerises PET — the crystal-clear plastic of every mineral-water and cola bottle.
- Antimony trisulfide (Sb₂S₃) striking sparks on the head of safety matches, and type metal for the old letterpress era.
◍ Everyday examples
- The battery that starts a bus or carries a Bangladeshi household through load-shedding holds antimony-hardened lead plates.
- Every clear PET drink bottle, from one-litre water to two-litre cola, was born through an antimony catalyst.
- A box of safety matches uses antimony trisulfide, while kajal continues stibnite’s five-millennium cosmetic story.
History & name
Antimony’s glossy black ore stibnite (Sb₂S₃) was ground into kohl eyeliner by the Egyptians over five thousand years ago. Medieval alchemists first coaxed out the pure metal, and the Italian metallurgist Vannoccio Biringuccio described it scientifically in his 1540 smelting treatise. The name journeyed from the Greek stimmi through the Arabic al-ithmid into medieval Latin antimonium, while the symbol Sb honours the Latin stibium; a colourful legend that it means “poison of monks” is charming — and false.