Discovered By: Gregory R. Choppin, Stanley Gerald Thompson, Bernard G. Harvey, Albert Ghiorso
Discovery year: 1952

The following table showing some properties of Einsteinium(Es):

Table Example
Atomic number 99
Group n/a
Period 7
Block f
Electrons 99
Protons 99
Neutron 153
Atomic weight (252)
Oxidation states +3
Ionic charge Es^3+


Table Example
Electrons per shell K2 L8 M18 N32 O29 P8 Q2
Electron configuration 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 6s^2 4f^14 5d^10 6p^6 7s^2 5f^11
Melting point 860°C
Phase Solid
Electonegativity 1.3
Valence 4
First ionization energy 619 kJ.mol^-1
Radioactive Yes
Half life 4.075*10^7 s
Lifetime 5.88*10^7 s


Table Example
Neutron cross section 160 barn
decay mode Alpha emission (α-decay)