Iridium
77
Ir
Gruppe
9
Periode
6
Blok
d
Protoner
Elektroner
Neutroner
77
77
115
Generelle Egenskaber
Atomnummer
77
Atommasse
192,217
Masseantal
192
Kategori
Overgangsmetaller
Farve
Sølv
Radioaktiv
Nej
From the Latin word iris meaning rainbow
Krystalstruktur
Fladecentreret Kubisk
Historie
Iridium was discovered in 1803 by English chemist Smithson Tennant in London.
Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue.
Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal.
Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue.
Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal.
Elektroner i hver skal
2, 8, 18, 32, 15, 2
Elektronkonfiguration
[Xe] 4f14 5d7 6s2
Iridium is the most corrosion-resistant metal known
Fysiske Egenskaber
Tilstandsform
Fast stof
Massefylde
22,56 g/cm3
Smeltepunkt
2739,15 K | 2466 °C | 4470,8 °F
Kogepunkt
4701,15 K | 4428 °C | 8002,4 °F
Smeltevarme
26 kJ/mol
Fordampningsvarme
560 kJ/mol
Varmefylde
0,131 J/g·K
Forekomst i jordskorpen
4×10-8%
Forekomst i universet
2×10-7%
CAS-nummer
7439-88-5
PubChem CID-nummer
23924
Atomare egenskaber
Atomradius
136 pm
Kovalent radius
141 pm
Elektronegativitet
2,2 (Paulings skala)
Ioniseringspotentiale
8,967 eV
Atomvolumen
8,54 cm3/mol
Varmeledningsevne
1,47 W/cm·K
Oxidationstrin
-3, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9
Anvendelser
Iridium is used in making crucibles and other equipment that is used at high temperatures.
Iridium is also used as a hardening agent in platinum alloys.
Its resistance to arc erosion makes iridium alloys ideal for electrical contacts for spark plugs.
Radioactive isotopes of iridium are used in radiation therapy for the treatment of cancer.
Iridium is also used as a hardening agent in platinum alloys.
Its resistance to arc erosion makes iridium alloys ideal for electrical contacts for spark plugs.
Radioactive isotopes of iridium are used in radiation therapy for the treatment of cancer.
Iridium is considered to be of low toxicity
Isotoper
Stabile isotoper
191Ir, 193IrUstabile isotoper
164Ir, 165Ir, 166Ir, 167Ir, 168Ir, 169Ir, 170Ir, 171Ir, 172Ir, 173Ir, 174Ir, 175Ir, 176Ir, 177Ir, 178Ir, 179Ir, 180Ir, 181Ir, 182Ir, 183Ir, 184Ir, 185Ir, 186Ir, 187Ir, 188Ir, 189Ir, 190Ir, 192Ir, 194Ir, 195Ir, 196Ir, 197Ir, 198Ir, 199Ir