Terbium

Kemiallinen merkki: Tb
Järjestysluku: 65
Kategoria: lantanoidit
Ryhmä: n/a
Jakso: 6
Lohko: f
Moolimassa: 158,92535 g/mol
Elektronia kuorilla: 2, 8, 18, 27, 8, 2
CAS-numero: 7440-27-9
Olomuoto: kiinteä
Tiheys: 8,23 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 1629 K (1356 °C, 2473 °F)
Kiehumispiste: 3503 K (3230 °C, 5846 °F)
Kiderakenne: hexagonal
Hapetusluvut: 3, 4
Elektronegatiivisuus: 1,2 (Pauling-asteikko)
Nimen alkuperä: terbia
Nimen tarkoitus: when the mineral yttria was partitioned into three fractions, the 'terbia' was the fraction that contained the pink color (due to what now is known as erbium)
Faktoja:
- is a silvery-white rare earth metal that is malleable, ductile and soft enough to be cut with a knife
- is reasonably stable in air (it does not tarnish after nineteen months at room temperature)
- two crystal allotropes exist, with a tran
- is used to dope calcium fluoride, calcium tungstate and strontium molybdate, materials that are used in solid-state devices, and as a crystal stabilizer of fuel cells which operate at elevated temperatures
- is also used in alloys and in th
- is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite
- the richest current commercial sources of terbium are the ion-adsorption clays of southern China
- can be produced by reducing the anhydrous chloride or fluoride with calcium metal in a tantalum crucible - calcium and tantalum impurities can be removed by vacuum remelting
- as with the other lantanidit, terbium compounds are of low to moderate toxicity, although their toxicity has not been investigated in detail