The chemical element of atomic number 99, a radioactive metal of the actinide series. Einsteinium does not occur naturally and was discovered in 1953 in debris from the first hydrogen bomb explosion. (Symbol: Es)
More example sentences
- They were named after two of the century's most creative physicists: einsteinium and fermium.
- All isotopes of einsteinium are radioactive, the most stable being einsteinium - 252 with a half life of 20.47 days.
- Atomic number 101 is a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles.
Definition of einsteinium in:
- The US English dictionary