PERIODIC ELEMENT
Cs (Cesium)

 



Atomic number : 55
Atomic mass : 132.9054 g.mol-1
Electronegativity according to Pauling : 0.7
Density : 1.9 g.cm-3 at 20 °C
Melting point : 28.4 °C
Boiling point : 669 °C
Vanderwaals radius : 0.267 nm
Ionic radius : 0.167 nm
Isotopes : 12
Electronic shell : [Xe] 6s1
Energy of first ionisation : 375.6 kJ.mol-1
Discovered by : Fustov Kirchhoff in 1860
Atomic Structure Uses (removes air traces in vacuum tubes)