Einsteinium

Einsteinium • Actinide Rare Earth

Symbol: Es
Date of discovery: 1952
Name origin: Albert Einstein
Appearance: unknown
Discoverer: Albert Ghiorso
Obtained from: man-made

Melting point: 1133 K
Boiling point: unknown
Density[kg/m³]: unknown
Molar volume: unknown
Protons/Electrons: 99
Neutrons: 153
Shell structure: 2,8,18,32,29,8,2
Electron configuration: [Rn]5f117s2
Oxidation state: 3
Crystal structure: unknown

Einsteinium, named after theoretical physicist and Nobel Prize winner Albert Einstein, is a synthetic element that is highly radioactive. It is produced by bombarding plutonium with neutrons. It was discovered in 1952 after two teams examined the debris of the first hydrogen bomb test. They found that einsteinium-253 was made by the nuclear fusion of 15 neutrons with uranium-238. Because of the tensions of the Cold War, these results were kept secret until 1955. In 1961, a sample weighing 0.01 mg of Es-253 was synthesized.