Symbol	Es
Atomic number	99
Group	-
Period	7
Block	f
Classification	Actinide

Appearance	Silver-colored
Color	-

Number of protons	99 p+
Number of neutrons	153 n0
Number of electrons	99 e-

From Wikipedia, the free encyclopediaEinsteinium is a synthetic element with symbol Es and atomic number 99. It is the seventh transuranic element, and an actinide. Einsteinium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952, and named after Albert Einstein.

Phase at STP	Solid
Density	8.84 g/cm3
Atomic weight	252 u

Melting point	1133 K 859.85 °C 1579.73 °F
Boiling point	1269 K 995.85 °C 1824.53 °F
Heat of vaporization	-

Electronegativity (Pauling Scale)	1.3
Electron affinity	-28.6 kJ/mol
Oxidation states	+2, +3, +4 ()
Ionization energies	619 kJ/mol 1216 kJ/mol 2334 kJ/mol 3734 kJ/mol

Electron configuration Shorthand configuration	[Rn] 5f11 7s2
Electron configuration Full configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f11 6s2 6p6 7s2
Electron configuration chart	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f11 6s2 6p6 7s2
Electrons per shell	2, 8, 18, 32, 29, 8, 2
Valence electrons	2
Valency electrons	3
Bohr model	Figure: Shell diagram of Einsteinium (Es) atom.
Orbital Diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 7s

Discovery

Lawrence Berkeley National Laboratory (1952)

CAS Number	7429-92-7
ChemSpider ID	22356
EC number	-
PubChem CID Number	23913