Es
Einsteinium · element 99
Actinide · Solid at room temperature
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.
Key facts
Atomic mass
252 u
how heavy one atom is
Phase (room temp.)
Solid
Density
8.84 g/cm³
how tightly packed it is
Melting point
1133 K (860 °C)
when solid turns to liquid
Boiling point
1269 K (996 °C)
when liquid turns to gas
Period
7
its row in the periodic table
Group
3
its column in the periodic table
Block
F-block
the neighbourhood it lives in
Electronegativity
1.3
how strongly it pulls electrons
Electron configuration
[Rn] 5f11 7s2
where its electrons live
Shells
2 · 8 · 18 · 32 · 29 · 8 · 2
electrons in each layer, inside to out
Discovered by
Lawrence Berkeley National Laboratory
who found it
Appearance
silver-colored
what it looks like
Source: Wikipedia