Thulium
Symbol
Tm
Atomic Number
69
Atomic Weight
168.93421
Element Classification
Discovered By
Per Theodor Cleve
Discovery Date
1879 (Sweden)
Name Origin
Thule, ancient name of Scandinavia.
Density(g/cc)
9.321
Melting Point
1818
Boiling Point(K)
2220
Appearance
Soft, malleable, ductile, silvery metal
Atomic Radius(pm)
177
Atomic Volume(cc/mol)
18.1
Covalent Radius(pm)
156
Ionic Radius
87 (+3e)
Specific Heat
0.160
Fusion Heat
n/a
Evaporation Heat(kj/mol)
232
Thermal Conductivity(@25°C W/m K)
(16.9)
Debye Temperature
n/a
Pauling Negativity Number
1.25
First Ionizing Energy(kj/mol)
589
Oxidation States
3, 2
Electronic Configuration
[Xe] 4f13 6s2
Lattice Structure
Hexagonal(HEX)
Lattice Constant
3.540
Lattice C/A Ratio
1.570
