WebElements

Periodic Table

einsteinium

Atomic number: 99
Atomic weight: 252
Symbol: Es
Group number: (actinide)
Electronic configuration: [Rn].5f11.7s2

Description

Einsteinium is radioactive rare earth metal named after Albert Einstein. It is of no commercial importance and only a few of its compounds are known.

General information

Discoveror: Workers at Argonne, Los Alamos, USA, and the University of California at Berkeley, USA.
Date discovered: 1952
Discovered at: USA
Meaning of name: Named after "Albert Einstein"

Physical data

Standard state: solid at 298 K
Colour: /TR>
1st619

Isotopes

This section gives some data for naturally occurring isotopes.
Nominal mass Accurate mass % natural abundance
nil

Further Information

Copyright 1997 Mark Winter
Department of Chemistry at the University of Sheffield, Sheffield S3 7HF, England.

The current version of this document is at http://www.shef.ac.uk/~chem/web-elements-I/Es.html