← Back to the periodic table
99
Es
[252]
Einsteinium
Actinides · Group 13 · Period 6–7 (f)
Atomic properties
| Atomic number | 99 |
|---|---|
| Symbol | Es |
| Standard atomic weight | [252] |
| Classification | Actinides |
| Group | f-block series |
| Period | 7 |
| Block | f-block (actinide) |
| Electron configuration | [Rn] 5f11 7s2 |
| Electronegativity (Pauling) | 1.30 |
| Common oxidation states | +3 |
Physical properties
| Phase at 20 °C | Solid |
|---|---|
| Density | 8.84 g/cm³ |
| Melting point | 860 °C |
| Boiling point | 996 °C |
| Discovered | 1952 |
| CAS number | — |