Iridium

77
Ir
Grupp
9
Period
6
Block
d
Protoner
Electrons
Neutroner
77
77
115
Generella Egenskaper
Atomnummer
77
Atommassa
192,217
Mass Number
192
Kategori
Övergångsmetaller
Färg
Silver
Radioaktiv
Nej
From the Latin word iris meaning rainbow
Kristallstruktur
Ytcentrerat kubiskt
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.
Elektroner per skal
2, 8, 18, 32, 15, 2
Elektronkonfiguration
[Xe] 4f14 5d7 6s2
Ir
Iridium is the most corrosion-resistant metal known
Fysikaliska Egenskaper
Aggregationstillstånd
Fast
Densitet
22,56 g/cm3
Smältpunkt
2739,15 K | 2466 °C | 4470,8 °F
Kokpunkt
4701,15 K | 4428 °C | 8002,4 °F
Smältvärme
26 kJ/mol
Ångbildningsvärme
560 kJ/mol
Specifik värmekapacitet
0,131 J/g·K
Abundance in Earth's crust
4×10-8%
Abundance in Universe
2×10-7%
Pieces
Bildkrediter: Images-of-elements
Pieces of pure iridium
CAS Number
7439-88-5
PubChem CID Number
23924
Atomära Egenskaper
Atomradie
136 pm
Kovalent radie
141 pm
Elektronegativitet
2,2 (Paulingskalan)
Jonisationspotential
8,967 eV
Molvolym
8,54 cm3/mol
Värmeledningsförmåga
1,47 W/cm·K
Oxidationstillstånd
-3, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9
Applications
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 considered to be of low toxicity
Isotoper
Stabila isotoper
191Ir, 193Ir
Instabila 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