Symbol Cs Atomic radius: pm 265 Fusion: kJ/Mole 2.09
Name Cesium Ionic radius: pm (+1)174 Boiling point: C 671
Atomic number 55 Electron affinity 0.47 Melting point: C 28
Atomic weight 132.9 1st  ion potential 3.89 Specific Heat Cap: J/(g K) 0.24
Classification Alkali metal Natural form Solid Thermal Cond: W/(cm K) 0.36
Configuration [Xe]6s1 Crystal structure BCC Electrical Cond 0.0489
Oxidation states 1 Density 1.93 Abundance: mg/kg-crust 3
Electronegativity 0.79 Vaporization: kJ/Mole 65.9    
Cesium was discovered in 1860 by Robert Bunsen and Gustav Kirchoff. Uses - photocells, IR lamps, removal of air traces in vaccuum tubes, ion propulsion systems,atomic clocks