Sb
Antimony is a metalloid used since ancient times as a cosmetic and in flame retardants.
Physical Properties
| Atomic Mass | 121.76 u |
| Density | 6.685 g/cm³ |
| Melting Point | 903.78 K |
| Boiling Point | 1860.0 K |
| Appearance | Silvery lustrous gray metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 2.05 (Pauling) |
| 1st Ionization Energy | 834.0 kJ/mol |
| Electron Affinity | 103.2 kJ/mol |
| Oxidation States | -3, +3, +5 |
Atomic Properties
| Electron Configuration | [Kr] 4d10 5s2 5p3 |
| Atomic Radius | 133.0 pm |
| Covalent Radius | 139.0 pm |
| Van der Waals Radius | 206.0 pm |
Discovery
| Discovered By | Known since antiquity |
| Location | Various (ancient Egypt) |
| Named After | Greek 'anti + monos' meaning not alone; symbol Sb from Latin 'stibium' |
About Antimony
Antimony is a lustrous gray metalloid found mainly as stibnite ore. Ancient Egyptians used antimony sulfide as eye cosmetics (kohl). It expands on cooling, a rare property shared with water and bismuth.
Uses & Applications
Flame retardants, lead-acid batteries, semiconductors, pewter, and bullets.
Fun Fact
Ancient Egyptians used antimony sulfide as eye makeup over 5,000 years ago, making it one of the earliest cosmetic ingredients.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 121 | 0.5721% | - | Yes |
| 123 | 0.4279% | - | Yes |
Electron Configuration
[Kr] 4d10 5s2 5p3