Iridij
77
Ir
Skupina
9
Perioda
6
Blok
d
Protoni
Elektroni
Neutroni
77
77
115
Opća svojstva
Atomski broj
77
Relativna atomska masa
192,217
Maseni broj
192
Kategorija
Prijelazni metali
Boja
Srebrna
Radioaktivan
Ne
Od latinske riječi iris, duga
Kristalna struktura
Kubna plošno centrirana
Povijest
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.
Elektrona po ljusci
2, 8, 18, 32, 15, 2
Elektronska konfiguracija
[Xe] 4f14 5d7 6s2
Iridium is the most corrosion-resistant metal known
Fizikalna svojstva
Agregacijsko stanje
Čvrsto
Gustoća
22,56 g/cm3
Talište
2739,15 K | 2466 °C | 4470,8 °F
Vrelište
4701,15 K | 4428 °C | 8002,4 °F
Toplina taljenja
26 kJ/mol
Toplina isparavanja
560 kJ/mol
Specifični toplinski kapacitet
0,131 J/g·K
Zastupljenost u Zemljinoj kori
4×10-8%
Zastupljenost u svemiru
2×10-7%
CAS broj
7439-88-5
PubChem CID broj
23924
Atomska svojstva
Atomski radijus
136 pm
Kovalentni radijus
141 pm
Elektronegativnost
2,2 (Paulingova ljestvica)
Potencijal ionizacije
8,967 eV
Atomski volumen
8,54 cm3/mol
Toplinska vodljivost
1,47 W/cm·K
Stanja oksidacije
-3, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9
Primjene
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
Izotopi
Stabilni izotopi
191Ir, 193IrNestabilni izotopi
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