Praseodyymi

Kemiallinen merkki: Pr
Järjestysluku: 59
Kategoria: lantanoidit
Ryhmä: n/a
Jakso: 6
Lohko: f
Moolimassa: 140,90765 g/mol
Elektronia kuorilla: 2, 8, 18, 21,8, 2
CAS-numero: 7440-10-0
Olomuoto: kiinteä
Tiheys: 6,77 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 1208 K (935 °C, 1715 °F)
Kiehumispiste: 3793 K (3520 °C, 6368 °F)
Kiderakenne: hexagonal
Hapetusluvut: 3
Elektronegatiivisuus: 1,13 (Pauling-asteikko)
Nimen alkuperä: prasios and didymos
Nimen tarkoitus: Greek words which mean green and twin because it is used in glasses to give a green color
Faktoja:
- is a soft, silvery, malleable and ductile metal
- develops a green oxide coating that spalls off when exposed to air, exposing more metal to oxidation - for this reason, praseodymium should be stored under a light mineral oil or sealed in g
- is frequently misspelled as praseodynium
- is available in small quantities in Earth's crust (9,5 ppm)
- is found in the rare earth minerals monazite and bastnasite, typically comprising about 5% of the lantanidit contained therein
- like all rare earths, praseodymium is of low to moderate toxicity
- has no known biological role
- is used in making aircraft engines, in carbon-arc lighting, in glassware making to give them a yellow color