Element Holmium
Part of the lanthanide series, holmium is a rare-earth element.
Holmium was discovered by Swedish chemist Per Theodor Cleve. Its oxide was first isolated from rare-earth ores in 1878. The element’s name comes from Holmia, the Latin name for the city of Stockholm.
Holmium is a chemical element with the symbol Ho and atomic number 67.
Names and Identifiers
| Chemical Formula: | Ho |
| CAS: | 7440-60-0 |
| Molecular Weight: | 164.930g/mol |
| EC Number : | 231-169-0 |
| MDL Number: | MFCD00011049 |
| Color: | silvery-white |
| Other Names: | Olmio, Hólmio |
| PubChem CID: | 23988 |
| IUPAC Name: | Holmium |
| Inchl: | InChI=1S/Ho |
| InChI Key: | KJZYNXUDTRRSPN-UHFFFAOYSA-N |
| Canonical SMILES: | [Ho] |
| ICSC Number: | n/a |
Physical & Chemical Properties
| Phase: | Solid |
| Density: | 8.79 g/cm³ |
| Boiling Point: | 2873 K (2600 °C, 4712 °F) |
| Melting Point: | 1734 K (1461 °C, 2662 °F) |
| Molecular Formula: | Ho |
| Flash Point: | n/a |
| Exact Mass: | 164.930298 |
| Symbol: |  |
| Signal Word: | Danger |
| Hazard Statements: | H228 |
| Precautionary Statements: | n/a |
| Hazard Codes: | F |
| Risk Phrases: | 11 |
| Safety Phrases: | n/a |
| RIDADR: | n/a |
| WGK Germany: | 3 |
| RTECS: | n/a |
| Packaging Group: | n/a |
| Hazard Class: | n/a |
Natural holmium contains one stable isotope, holmium-165. Some synthetic radioactive isotopes are known; the most stable one is holmium-163, with a half-life of 4570 years.
Naturally occurring isotopes
| Isotope | Mass/Da | Natural abundance (atom %) | Nuclear spin (I) | Magnetic moment (μ/μN) |
|---|---|---|---|---|
| 165Ho | 164.930319 (4) | 100 | 7/2 | 4.173 |
Radiosotope data
| Isotope | Mass/Da | Half-life | Mode of decay | Nuclear spin | Nuclear magnetic moment |
|---|---|---|---|---|---|
| 161Ho | 160.927852 | 2.48 h | EC to 161Dy | 7/2 | 4.25 |
| 162Ho | 161.929092 | 15 m | EC to 161Dy | 1 | |
| 163Ho | 162.928730 | 4570 y | EC to 161Dy | 7/2 | 4.23 |
| 164Ho | 163.930231 | 29 m | EC to 161Dy; β– to 164Er | 1 | |
| 166Ho | 165.932281 | 1.117 d | β– to 166Er | 0 | |
| 167Ho | 166.933127 | 3.1 h | β– to 167Er | 7/2 |