Boori

Kemiallinen merkki: B
Järjestysluku: 5
Kategoria: puolimetallit
Ryhmä: 13
Jakso: 2
Lohko: p
Moolimassa: 10,811 g/mol
Elektronia kuorilla: 2, 3
CAS-numero: 7440-42-8
Olomuoto: kiinteä
Tiheys: 2,08 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 2349 K (2076 °C, 3769 °F)
Kiehumispiste: 4200 K (3927 °C, 7101 °F)
Kiderakenne: rhombohedral
Hapetusluvut: 4, 3, 1
Elektronegatiivisuus: 2,04 (Pauling-asteikko)
Nimen alkuperä: buraq or burah
Nimen tarkoitus: the Arabic and Persian words for the mineral borax
Faktoja:
- occurs abundantly in the evaporite ores borax and ulexite
- several allotropes of boron exist; amorphous boron is a brown powder, though crystalline boron is black, extremely hard (9,3 on Mohs' scale), and a weak conductor at room temperatu
- is used as a dopant in the semiconductor industry, while boron compounds play important roles as light structural materials, insecticides and preservatives, and reagents for chemical synthesis
- is an essential plant nutrient, although high soil concentrations of boron may also be toxic to plants
- elemental boron is nontoxic and common boron compounds such as borates and boric acid have low toxicity (approximately similar to table salt with the lethal dose being 2 to 3 grams per kilogram) and therefore do not require special precautions while handling nearly all boron ore extracted from the Earth is destined for refinement into boric acid and sodium tetraborate