Antimony (Sb)

Antimony is a lustrous gray metalloid found in nature mainly as the sulfide mineral stibnite.

Core Principles & Analysis

• Antimony compounds have been used since antiquity, with the sulfide mineral stibnite serving as kohl eye cosmetic in ancient Egypt.
• It is a brittle metalloid that, unusually, expands slightly as it solidifies, which made it valuable in sharply cast printing type.
• Antimony trioxide is a major flame-retardant synergist, and the metal hardens the lead grids of lead-acid batteries.

Specifications & Metrics

• NUM: 51
• SYMBOL: Sb
• CATEGORY: Metalloid
• ATOMIC MASS: 121.76 u
• ELECTRONEGATIVITY: 2.05 Pauling
• ATOMIC RADIUS: 206 pm
• IONIZATION ENERGY: 8.64 eV
• ELECTRON AFFINITY: 1.07 eV
• MELTING POINT: 903.78 K
• BOILING POINT: 1860 K
• DENSITY: 6.685 g/cm³
• ELECTRON CONFIGURATION: [Kr]5s2 4d10 5p3
• OXIDATION STATES: +5, +3, -3
• STANDARD STATE: Solid
• GROUP BLOCK: Metalloid
• YEAR DISCOVERED: Ancient