
Element Name: Einsteinium
Atomic Number: 99
Symbol: Es
Atomic Weight: (254)
Discovery: Ghiorso et al. 1952
Electron Configuration: 5f11
Group: Rare Earth, Actinides
Melting Point: 1133.2 K
1st Ionization Energy: 619 kJ/mole
Electronegativity: 1.3
Shells: 2,8,18,32,29,8,2
Characteristics: Radioactive
Atomic Radius: 186 pm
Source: Man-made
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange’s Handbook of Chemistry (1952)