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99Es252 u

Einsteinium

actinide
Atomic Number
99
Atomic Mass
252 u
Period
7
Group
3

Quick Facts

PropertyValue
SymbolEs
Atomic Number99
Atomic Mass[252] u
CategoryActinide
Period7
Group3
Blockf
Electron Configuration[Rn] 5f¹¹ 7s²

History and Discovery

Discovered by: Albert Ghiorso and colleagues Year of Discovery: 1952 Location: Discovered in debris from first hydrogen bomb test (Ivy Mike)

Etymology

Named after Albert Einstein.

Interesting Facts

  1. Discovered in nuclear explosion debris
  2. Named after Albert Einstein
  3. Only microgram quantities have been produced
  4. Glows visibly due to radioactive decay
  5. First identified in fallout from thermonuclear testing