Einsteinium (Es), element 99 – Learn Acer periodic table

Einsteinium

Actinide, atomic number 99.

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.

Facts

Symbol Es. Atomic mass 252.0 u. Group 3, period 7. Electron configuration [Rn] 5f11 7s2. Electrons per shell 2, 8, 18, 32, 29, 8, 2. State at room temperature: Solid. Melting point 859.9 °C, boiling point 995.9 °C. Discovered by Lawrence Berkeley National Laboratory.

Element data from Wikipedia, CC BY-SA 3.0.