Antimony (Sb)
Element 51 · Metalloid
Antimony (Sb) is a chemical element with atomic number 51. It is classified as a metalloid in period 5, group 15 of the periodic table (the p-block). Its standard atomic weight is 121.76 u and its ground-state electron configuration is [Kr] 4d¹⁰ 5s² 5p³.
Antimony facts
| Atomic number (Z) | 51 |
|---|---|
| Symbol | Sb |
| Standard atomic weight | 121.76 u |
| Category | Metalloid |
| Group | 15 |
| Period | 5 |
| Block | p-block |
| Electron configuration | [Kr] 4d¹⁰ 5s² 5p³ |
| Electronegativity (Pauling) | 2.05 |
| State at 20 °C | Solid |
| Protons / electrons | 51 / 51 |
| Neutrons (most common isotope, approx.) | 71 |
| Molar mass | 121.76 g/mol |