Samarium

Kemiallinen merkki: Sm
Järjestysluku: 62
Kategoria: lantanoidit
Ryhmä: n/a
Jakso: 6
Lohko: f
Moolimassa: 150,36 g/mol
Elektronia kuorilla: 2, 8, 18, 24, 8, 2
CAS-numero: 7440-12-2
Olomuoto: kiinteä
Tiheys: 7,52 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 1345 K (1072 °C, 1962 °F)
Kiehumispiste: 2067 K (1794 °C, 3261 °F)
Kiderakenne: rhombohedral
Hapetusluvut: 3
Elektronegatiivisuus: 1,17 (Pauling-asteikko)
Nimen alkuperä: samarskite
Nimen tarkoitus: a mineral found in the Urals and in North Carolina
Faktoja:
- is a rare earth metal, with a bright silver luster
- is reasonably stable in air; it ignites in air at 150 °C
- even with long-term storage under mineral oil, samarium is gradually oxidized, with a grayish- yellow powder of the oxide-hydro
- the metallic appearance of a sample can be preserved by sealing it under an inert gas such as argon
- is used e,g, in carbon-air lighting, as a neutron absorber, for alloys, for headphone magnets
- is never found free in nature, but, like other rare earth elements, is contained in many minerals, including monazite, bastnäsite and samarskite
- is of low to moderate toxicity, although their toxicity has not been investigated in detail
- is composed of four stable isotopes, and three extremely long-lived radioisotopes