Hopea

Kemiallinen merkki: Ag
Järjestysluku: 47
Kategoria: siirtymämetallit
Ryhmä: 11
Jakso: 5
Lohko: d
Moolimassa: 107,8682 g/mol
Elektronia kuorilla: 2, 8, 18, 18, 1
CAS-numero: 7440-22-4
Olomuoto: kiinteä
Tiheys: 10,49 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 1234,93 K (961,78 °C, 1763,2 °F)
Kiehumispiste: 2435 K (2162 °C, 3924 °F)
Kiderakenne: face centered cubic
Hapetusluvut: 1, 2, 3
Elektronegatiivisuus: 1,93 (Pauling-asteikko)
Nimen alkuperä: seolfor
Nimen tarkoitus: 'silver', although the symbol comes from the word argentum, meaning white or shining
Faktoja:
- has the highest electrical conductivity of any element and the highest thermal conductivity of any metal
- most silver is produced as a by-product of copper, gold, lead, and zinc refining
- has been known since ancient times and has long been valued as a precious metal, used to make ornaments, jewelry, high-value tableware, utensils (hence the term silverware), and currency coins
- today, silver metal is used in electrical contacts and conductors, in mirrors and in catalysis of chemical reactions
- is stable in pure air and water, but tarnishes when it is exposed to air or water containing ozone or hydrogen sulfide to layer of silver sulfide which can be cleaned off with dilute hydrochloric acid
- plays no known natural biological role in humans, and possible health effects of silver are a subject of dispute, Silver itself is not toxic but most silver salts are, and some may be carcinogenic