Einsteinium

man-made radioisotope; identified by Ghiorso and colleagues at Berkeley in December 1952, as part of debris from first large thermonuclear explosion; chemical properties similar to those of holmium; ionic radius of Es+++ is 0.0925 nm; has lowest enthalpy of vaporization of any of the divalent elements; cub, a=0.575 nm; discovered in 1952; t1/2 of 253Es is 20.5 days, t1/2 of 254Es is 276 days, t1/2 of 255Es is 40 days [HAW93] [KIR78]

Einsteinium atom is an actinoid atom and a f-block element atom.|A man-made radioactive actinide with atomic symbol Es, and atomic number 99. Its known isotopes range in mass number from 240-258. Its valence can be +2 or +3. Einsteinium was originally discovered in the debris from a thermonuclear explosion in 1952.

Molecular Weight:252.0830
Exact Mass:252.0830
Monoisotopic Mass:252.0830
Heavy Atom Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes