67
Ho
Holmium
165
Holmium (Ho)
LanthanidePeriod 6f-block-block
Holmium is a chemical element with symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve.
Latin name: Holmium
Atomic Number
67
Atomic Mass
165 g/mol
Phase (STP)
Solid
Electron Config.
[Xe] 4f¹¹ 6s²
General
SymbolHo
Atomic Number67
Atomic Mass165 g/mol
CategoryLanthanide
Period6
Blockf-block
Electron Configuration[Xe] 4f¹¹ 6s²
Valence Electrons13
Coloursilvery-white metallic
Appearancesilvery white
CAS NumberCAS7440-60-0
Physical Properties
Phase (STP)Solid
Density8.8 g/cm³
Melting Point1473.85°C · 2684.93°F · 1747.00 K
Boiling Point2699.85°C · 4891.73°F · 2973.00 K
Atomic Properties
Atomic Radius216 pm
Electronegativity1.23 Pauling
Ionization Energy581 kJ/mol
Oxidation States+3
Ion ChargeHo3+
Thermodynamic
Molar Heat27.15 J/(mol·K)
Crystal Structure
Crystal Structurehexagonal close-packed
Mechanical Properties
Mohs Hardness4
Nuclear & Hazards
Half-lifestable (Ho-165)
Abundance
In Universe0.00002%
In Sun0.000015%
In Earth's Crust0.0120%
In Meteorites0.00009999999999999999%
Discovery & History
Discovery Year1878
Discovered ByPer Teodor Cleve
Country of DiscoverySweden
Isotopes of Holmium
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Ho-165 | 100% | Stable | — |