99 - Einsteinium actinide
Discovered by Lawrence Berkeley Laboratory in 1952
- Atomic Radius (Å)
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.
Shell | Electrons | Orbitals |
---|---|---|
1 | 2 | 2 in 1s |
2 | 8 | 2 in 2s + 6 in 2p |
3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
4 | 32 | 2 in 4s + 6 in 4p + 10 in 4d + 14 in 4f |
5 | 29 | 2 in 5s + 6 in 5p + 10 in 5d + 11 in 5f |
6 | 8 | 2 in 6s + 6 in 6p |
7 | 2 | 2 in 7s |
252 u
Atomic Mass
8.84 g/cm³
Density
-2.86e+1
Electron Affinity
1.3
Electronegativity
6.42 eV
First Ionization Energy
1133.15 K
Melting Point
7
Number of Shells
99
Atomic Number