Iridium
77
Ir
Ryhmä
9
Jakso
6
Lohko
d
Protonia
Elektronit
Neutronia
77
77
115
Yleiset ominaisuudet
Järjestysluku
77
Atomipaino
192,217
Massaluku
192
Luokka
Siirtymäalkuaineet
Väri
Hopea
Radioaktiivisuus
Ei
From the Latin word iris meaning rainbow
Kiderakenne
Pintakeskinen kuutiollinen
Historia
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.
Elektroneja elektronikuorilla
2, 8, 18, 32, 15, 2
Orbitaalirakenne
[Xe] 4f14 5d7 6s2
Iridium is the most corrosion-resistant metal known
Fyysiset ominaisuudet
Olomuoto
Kiinteä
Tiheys
22,56 g/cm3
Sulamispiste
2739,15 K | 2466 °C | 4470,8 °F
Kiehumispiste
4701,15 K | 4428 °C | 8002,4 °F
Sulamislämpö
26 kJ/mol
Höyrystymislämpö
560 kJ/mol
Ominaislämpökapasiteetti
0,131 J/g·K
Esiintyvyys maankuoressa
4×10-8%
Esiintyvyys maailmankaikkeudessa
2×10-7%
CAS-numero
7439-88-5
PubChem CID-numero
23924
Atomiominaisuudet
Atomisäde
136 pm
Kovalenttisäde
141 pm
Elektronegatiivisuus
2,2 (Paulingin asteikko)
Ionisoitumispotentiaali
8,967 eV
Moolitilavuus
8,54 cm3/mol
Lämmönjohtavuus
1,47 W/cm·K
Hapetusluvut
-3, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9
Käyttö
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
Isotooppi
Vakaat isotoopit
191Ir, 193IrEpävakaat isotoopit
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