Thulium

Thulium Element Properties

f68
Er
Erbium
f69
Tm
Thulium
f70
Yb
Ytterbium
General
NameThulium
SymbolTm
Number69
Group NumberNA
GroupRare Earth, Lanthanides
Blockf
Density9.33 g/cm3
Atomic Weight168.9342 g/mol
Atomic Volume18.1
Discover1879


States
StateSolid
Melting Point1818 K
Boiling Point2223 K
Triple PointNil
Critical PointNil
Heat of Fusion16.84 kJ/mol
Heat of Vaporization247 kJ/mol


Energies
First Ionization Energy596.7 kJ/mole
Second Ionization Energy1163 kJ/mole
Third Ionization Energy2544 kJ/mole
Electronegativity1.25
Electron Affinity50 kJ/mole
Specific Heat0.16 J/gK
Heat Atomization232 kJ/mole atoms


Oxidation and Electrons
Shells2,8,18,31,8,2
Electron Configuration[Xe] 4f13 6s2
Minimum Oxidation Number0
Maximum Oxidation Number3
Minimum Common Oxidation Number0
Maximum Common Oxidation Number3


Appearance and Characteristics
Crystal Structurehexagonal
Characteristicssoft
Colorsilvery-white
Usesalloys
HardnessNil
ToxicityNone


Reactions
Reaction with Airvigorous, =>Tm2O3
Reaction with 6M HClmild, =>H2, TmCl3
Reaction with 15M HNO3mild, =>Tm(NO3)3
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes1
HydrideTmH2 TmH3
OxideTm2O3
ChlorideTmCl2 TmCl3


Radius
Atomic Radius176 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)117 pm
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)102 pm


Conductivity
Thermal Conductivity16.9 J/m-sec-deg
Electrical Conductivity13.5 1/mohm-cm
Polarizability21.8 A3


Abundance
SourceMonazite(phosphate),bastnaesite
Relation Abundance Solar System-1.423 log
Abundance Earth's Crust-0.3 log


f68
Er
Erbium
f69
Tm
Thulium
f70
Yb
Ytterbium