67
164.93

Ho

Holmium

Identification

CAS Number: 7440-60-0
Discovery Year: 1878
Discoverer: J.L. Soret
Discovery Location: Switzerland

Properties

Atomic Mass: 164.93033 Density: 8.8 g/cm³
Crust Abundance: 1.3 mg/kg
Crystal Structure: HEX

Atomic Dimensions

Atomic Radius: 175 pm
Atomic Radius (Rahm): 273 pm
Covalent Radius: 192 pm
Van der Waals Radius: 229.99999999999997 pm
Atomic Volume: 18.7 cm³/mol
Lattice Constant: 3.58 Å

Electronic Structure

Electron Config: [Xe] 4f11 6s2
Block: f
Period: 6 Electronegativity: 1.23
Oxidation States: +3

Abundance & Geochemistry

Crust Abundance: 1.3 mg/kg
Sea Abundance: 2.2e-7 mg/L
Geochemical Class: rare earth & related
Goldschmidt Class: litophile

About

Relatively soft and malleable silvery-white metallic element, which is stable in dry air at room temperature. It oxidizes in moist air and at high temperatures. It belongs to the lanthanoids. A rare-earth metal, it is found in the minerals monazite and gadolinite. It possesses unusual magnetic properties. One natural isotope, Ho-165 exists, six radioisotopes exist, the most stable being Ho-163 with a half-life of 4570 years. Holmium is used in some metal alloys, it is also said to stimulate the metabolism. Discovered by Per Theodor Cleve and J.L. Soret in Switzerland in 1879. The name homium comes from the Greek word Holmia which means Sweden. While all holmium compounds should be considered highly toxic, initial evidence seems to indicate that they do not pose much danger. The metal's dust however, is a fire hazard.

Isotopes

Ho-165 165 100.00%