Einsteinium

Description

Einsteinium is a synthetic transuranic element. It was discovered in the debris of the first hydrogen bomb explosion in 1952, and named after Albert Einstein. There is almost no use for any isotope of einsteinium outside of basic scientific research aiming at production of higher transuranic elements and transactinides. Einsteinium-254 was used as the calibration marker in the chemical analysis spectrometer of the Surveyor 5 lunar probe. The large mass of this isotope reduced the spectral overlap between signals from the marker and the studied lighter elements of the lunar surface.

Chemical Properties

Appearance	Silver-Colored Solid
Atomic Number	99
Atomic Weight	252 g/mol
Block	f
CAS Number	7429-92-7
Density	8.84 g/cm3
Electron Configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2 4d10 5p6 4f14 5d10 6s2 6p6 5f11 7s2
Ionization Energy	619 KJ/mol
Melting Point	860 °C
Oxidation State	2,3,4
Period	7
Symbol	Es