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

The following table showing some properties of Fermium(Fm):

Table Example
Atomic number 100
Group n/a
Period 7
Block f
Electrons 100
Protons 100
Neutrons 157
Atomic weight (257)
Oxidation states +3
Ionic charge Fm^3+


Table Example
Electrons per shell K2 L8 M18 N32 O30 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^12
Melting point 1527°C
Electronegativity 1.3
Valence 3
First ionization energy 627 kJ.mol^-1
Radioactive Yes
Half life 8.683*10^6 s
Lifetime 1.6253*10^6 s
Neutron cross section 5800 barn
Decay mode Alpha emission (α-decay)