Symbol Tm Atomic radius: pm 173 Fusion: kJ/Mole 16.84
Name Thulium Ionic radius: pm (+3)109 Boiling point: C 1950
Atomic number 69 Electron affinity - Melting point: C 1545
Atomic weight 168.9 1st  ion potential 6.18 Specific Heat Cap: J/(g K) 0.16
Classification Trans metal Natural form Solid Thermal Cond: W/(cm K) 0.17
Configuration [Xe]4f136s2 Crystal structure Hex Electrical Cond 0.0150
Oxidation states 2,3 Density 9.32 Abundance: mg/kg-crust 0.52
Electronegativity 1.25 Vaporization: kJ/Mole 247.0    
Thulium was discovered in 1879 along with holmium by Per Teodor Cleve. Uses - alloys, power for portable x-ray machnies