PERIODIC ELEMENT
Th (Thorium)

 



Atomic number : 90
Atomic mass : 232.04 g mol-1
Electronegativity according to Pauling : 1.3
Density : 11.72 g cm-3 at 20 °C
Melting point : 1750 °C
Boiling point : 4790 °C
Vanderwaals radius : 0.182 nm
Ionic radius : 0.110 nm (+4)
Isotopes : 9
Electronic shell : [ Rn ] 6d2 7s2
Energy of first ionisation : 1107.6  kJ.mol-1
Energy of second ionisation : 1962.4 kJ.mol-1
Energy of third ionisation : 2774 kJ.mol-1
Discovered by : Jons Berzelius in 1828
 
Atomic Structure Uses(strong alloys, ultraviolet photoelectric cells)