Holmium (Ho)
Holmium is element 67, a lanthanide in period 6 of the periodic table. At room temperature it is a solid.
Electron configuration [Xe] 4f11 6s2
Electrons per shell 2, 8, 18, 29, 8, 2
Holmium data
| Atomic number | 67 |
|---|---|
| Symbol | Ho |
| Atomic mass | 164.93 u |
| Category | Lanthanide |
| Group | — (f-block) |
| Period | 6 |
| Block | f |
| State at 25 °C | solid |
| Melting point | 1747 K (1473.9 °C) |
| Boiling point | 2973 K (2699.9 °C) |
| Density | 8.795 g/cm³ |
| Electronegativity (Pauling) | 1.23 |
| Atomic radius | — |
| 1st ionization energy | 581 kJ/mol |
| Electron affinity | -50 kJ/mol |
| Oxidation states | +3 |
| Common ion charge | 3+ |
| Discovered | 1878 |
Orbital diagram
Each box is one orbital holding up to two electrons of opposite spin. Following Hund’s rule, electrons spread out singly across a subshell before pairing.
Work through holmium’s configuration and its ions →
Where holmium sits
Holmium belongs to the lanthanides. Its Pauling electronegativity of 1.23 is mid-range; see the electronegativity chart and periodic trends for context. To use its mass in a calculation, try the molar mass calculator.
Holmium FAQ
What is the electron configuration of holmium?
Holmium (Z = 67) has the configuration 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f11 6s2. In noble-gas shorthand that is [Xe] 4f11 6s2.
How many valence electrons does holmium have?
2 (2 in the outer s subshell).
What is the atomic mass of holmium?
The standard atomic weight of holmium is 164.93 u, so one mole weighs 164.93 g.
Is holmium a metal?
Yes. Holmium is a lanthanide.
What is the charge of a holmium ion?
Holmium most commonly forms Ho3+.