Search Result for "einsteinium": 
Wordnet 3.0

NOUN (1)

1. a radioactive transuranic element produced by bombarding plutonium with neutrons;
[syn: einsteinium, Es, E, atomic number 99]


The Collaborative International Dictionary of English v.0.48:

Es \Es\ n. the chemical symbol for einsteinium, a transuranic element with atomic number 99. The atomic weight of the longest-lived isotope, with a half-life of 276 days, is 254. The first isotope discovered, having atomic weight 253 and a half-life of 20 days, was recognized in 1952 in the debris from a hydrogen bomb test. As much as 3 micrograms of einsteinium were produced by a complex process involving long irradiation of plutonium isotopes in nuclear reactors. Its chemical properties are those of a trivalent actinide element. --HCP61 Syn: einsteinium, atomic number 99. [WordNet 1.5 +PJC]
WordNet (r) 3.0 (2006):

einsteinium n 1: a radioactive transuranic element produced by bombarding plutonium with neutrons [syn: einsteinium, Es, E, atomic number 99]
The Elements (07Nov00):

einsteinium Symbol: Es Atomic number: 99 Atomic weight: (254) Appearance is unknown, however it is most probably metallic and silver or gray in color. Radioactive metallic transuranic element belonging to the actinoids. Es-254 has the longest half-life of the eleven known isotopes at 270 days. First identified by Albert Ghiorso and associates in the debris of the 1952 hydrogen bomb explosion. In 1961 the first microgram quantities of Es-232 were separated. While einsteinium never exists naturally, if a sufficient amount was assembled, it would pose a radiation hazard.