99Es252.0830
Einsteinium
Actinide
Solid at STP
Period 7Block FDiscovered 1952
[Rn]7s2 5f11
Einsteinium is a synthetic element with symbol Es and atomic number 99. It is the seventh transuranic element, and an actinide. Einsteinium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952, and named after Albert Einstein.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 99 |
| Atomic Mass | 252.0830 u |
| Electron Configuration | [Rn]7s2 5f11 |
| Oxidation States | +3 |
| Electronegativity | 1.3 (Pauling) |
| Atomic Radius | 245 pm |
| Ionization Energy | 6.42 eV |
| Block | F |
Physical Properties
| Appearance | silver-colored |
| Standard State | Solid |
| Melting Point | 1133 K (859.9 °C) |
| CPK Color | #B31FD4 |
Classification
| Category | Actinide |
| Group Block | Actinide |
| Period | 7 |
| Block | F |
Discovery
| Year Discovered | 1952 |
| Discovered By | Lawrence Berkeley National Laboratory |
| Electron Shells | 2, 8, 18, 32, 29, 8, 2 |