Atomic number:67
Group numbers:3
Period:6
Electronic configuration:[Xe] 4f11 6s2
Formal oxidation number:+3
Electronegativities:1.23
Atomic radius / pm:174.3
Relative atomic mass:164.93032 ± 0.00002
Holmium was discovered by Per Theodore Cleve (SE) in 1879. The origin of the name comes from the Greek word Holmia meaning Stockholm. It is a fairly soft, malleable, lustrous, silvery metal that reacts slowly with oxygen and water. Holmium dissolves in acids and is able to react violently with air or halogens. Holmium occurs in gadolinite but most often it's produced from monazite sand. It has very few practical applications; however, it has some unusual magnetic properties that offer some hope for future applications.
Density / g dm-3:8795 (298 K)
Molar volume / cm3mol-1:18.75 (298 K)
Electrical resistivity / μΩcm:87 (20 °C)
Thermal conductivity / W m-1K-1:16.2
Melting point / °C:1474
Boiling point / °C:2700
Heat of fusion / kJ mol-1:17.2
Heat of vaporization / kJ mol-1:303
Heat of atomization / kJ mol-1:302.63
First ionization energy / kJ mol-1:580.99
Second ionization energy / kJ mol-1:1138.54
Third ionization energy / kJ mol-1:2203.74
in the atmosphere / ppm:-
in the Earth's crust / ppm:0.78
in the oceans / ppm:0.00000008
Crystal structure:
hexagonal
Unit-cell dimensions / pm:
a=357.73, c=561.58
Space group:
P63/mmc
| 66 Dysprosium <= |
67 Holmium
|
=> 68 Erbium |