Antimony (Sb) — Element 51

51 Sb 121.76

Antimony

Element 51 · 121.76 u · p-block

metalloid

A lustrous metalloid used since ancient times as eye makeup (kohl). Now used in flame retardants and lead-acid batteries.

Phase (STP)

Solid

Melting Point

630.63 °C

Boiling Point

1587 °C

Density

6.685 g/cm³

Electronegativity

2.05

Atomic Radius

145 pm

Ionization Energy

834 kJ/mol

Electron Affinity

101 kJ/mol

Discovered

Ancient · Known since antiquity

Electron Configuration

[Kr] 4d10 5s2 5p3