Uraani

Kemiallinen merkki: U
Järjestysluku: 92
Kategoria: aktinoidit
Ryhmä: n/a
Jakso: 7
Lohko: f
Moolimassa: 238,02891 g/mol
Elektronia kuorilla: 2, 8, 18, 32, 21, 9, 2
CAS-numero: 7440-61-1
Olomuoto: kiinteä
Tiheys: 19,1 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 1405,3 K (1132,3 °C, 2070 °F)
Kiehumispiste: 4404 K (4131 °C, 7468 °F)
Kiderakenne: orthorhombic
Hapetusluvut: 3, 4, 5, 6
Elektronegatiivisuus: 1,38 (Pauling-asteikko)
Nimen alkuperä: Uranus
Nimen tarkoitus: the planet in the Solar System
Faktoja:
- is a silvery white, weakly radioactive metal, which is slightly softer than steel, strongly electropositive and a poor electrical conductor
- is malleable, ductile, and slightly paramagnetic
- has very high density, being approximately 70% de
- in nature, uranium atoms exist as uranium-238 (99,284%), uranium-235 (0,711%),[2] and a very small amount of uranium-234 (0,0058%)
- is used e,g, in the nuclear reactors, bombs and as a colorant in uranium glass, producing orange- red to le
- the half-life of uranium-238 is about 4,47 billion years and that of uranium-235 is 704 million years, making them useful in dating the age of the Earth
- normal functioning of the kidney, brain, liver, heart, and other systems can be affec uranium exposure, because, in addition to being weakly radioactive, uranium is a toxic metal
- finely divided uranium metal presents a fire hazard because uranium is pyrophoric; small grains will ignite spontaneously in air at room temperature