Einsteinium
actinide · period 7 · group 3 · f-block
Einsteinium is a synthetic element with the symbol Es and atomic number 99. Einsteinium is a member of the actinide series and it is the seventh transuranic element.
What the numbers say
At standard temperature and pressure Einsteinium is a solid, sitting in period 7, group 3 of the f-block.
Its melting point of 1133 K (860 °C) is the 56th highest of the 110 elements with a measured value — mid-range among the elements.
Pauling electronegativity is 1.3. Paired with oxygen (3.44) that is a difference of 2.14, which puts the bond predominantly ionic — expect a stable oxide ceramic.
It is reported in 2 oxidation states (2, 3), which sets how many distinct compounds and phases it can form.
First identified in 1952.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Es — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 32 · O 29 · P 8 · Q 2
Properties
| Atomic number | 99 |
|---|---|
| Atomic mass | 252 u |
| Series | actinide |
| Group | 3 |
| Period | 7 |
| Block | f-block |
| Phase at STP | Solid |
| Melting point | 1133 K (860 °C) |
| Boiling point | 1269 K (996 °C) |
| Electronegativity (Pauling) | 1.3 |
| Electron configuration | [Rn] 5f¹¹ 7s² |
| Oxidation states | 2,3 |
| Discovered | 1952 |
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See Es in context with all 118 elements.
Working with einsteinium in a real design?
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