Einsteinium

Atomic symbol: Es
Atomic number: 99
Atomic mass: 252

Appearance: Silver solid at 25°C

Group: N/a Period: 7
Series: Actinides
Block: f
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹¹ 7s²

Highly radioactive metal that glows blue in the dark.

Fun Fact! Named in honor of Albert Einstein, the scientist who discovered einsteinium was also named Albert (Albert Ghiorso).