Holmium (Ho)
Stable Isotopes of Holmium
| Isotope | Z(p) | N(n) | Atomic Mass | Natural Abundance | Nuclear Spin |
| Ho-165 | 67 | 98 | 164.930319 | 100.00% | 7/2- |
Holmium was discovered in 1878 by Marc Delafontaine and Jacques-Louis Soret. Its name comes from the Greek word Holmia, meaning “Sweden.”
A soft, lustrous metal with a silver-like appearance, holmium is a hexagonal crystalline solid with a metallic luster. It has one of the highest nuclear moments of any rare earth. It is paramagnetic, with a magnetic moment of 11.2 Bohr magnetons. It reacts slowly with water and is soluble in dilute acids. The metal forms fluoride, hydroxide, phosphate, oxalate and carbonate that are insoluble in water. Its water-soluble salts are chloride, bromide, iodide, acetate, nitrate and sulfate. Reactions of holmium with acids yield corresponding salts. The finely divided metal burns in oxygen at ordinary temperatures.
Holmium metal does not have significant commercial application. However, because of its unusual magnetic properties, it is being used in research studies to explore the magnetic and alloying behaviors of metals.
Properties of Holmium
| Name | Holmium |
| Symbol | Ho |
| Atomic number | 67 |
| Atomic weight | 164.93 |
| Standard state | Solid at 298 ºK |
| CAS Registry ID | 7440-60-0 |
| Group in periodic table | N/A |
| Group name | Lanthanoid |
| Period in periodic table | 6 (Lanthanoid) |
| Block in periodic table | f-block |
| Color | Silvery white |
| Classification | Metallic |
| Melting point | 1472 °C |
| Boiling point | 2695 °C |
| Vaporization point | 2694 ºC |
| Thermal conductivity | 16.2 W/(m·K) |
| Electrical resistivity | 87.0 µΩ·cm at 25 ºC |
| Electronegativity | 1.2 |
| Specific heat | 0.38 kJ/kg K |
| Heat of vaporization | 265 kJ·mol-1 |
| Heat of fusion | 17 kJ·mol-1 |
| Density of liquid | 8.34 g/cm3 at 1472 °C |
| Density of solid | 8.78 g/cm3 |
| Electron configuration | [Xe]4f116s2 |
| Metallic radius | 1.767 Å (coordination number 12) |
| Atomic volume | 18.78 cm3/mol |
| Oxidation state | +3 |
