Iridij

77
Ir
Skupina
9
Perioda
6
Blok
d
Protons
Electrons
Neutrons
77
77
115
General Properties
Vrstno število
77
Atomska teža
192,217
Mass Number
192
Kategorija
Prehodne kovine
Barva
Silver
Radioactive
Ne
From the Latin word iris meaning rainbow
Kristalna struktura
Ploskovno centrirana kubična
Zgodovina
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.
Electrons per shell
2, 8, 18, 32, 15, 2
Razporeditev elektronov
[Xe] 4f14 5d7 6s2
Ir
Iridium is the most corrosion-resistant metal known
Physical Properties
Faza snovi
Trdnina
Gostota
22,56 g/cm3
Tališče
2739,15 K | 2466 °C | 4470,8 °F
Vrelišče
4701,15 K | 4428 °C | 8002,4 °F
Talilna toplota
26 kJ/mol
Izparilna toplota
560 kJ/mol
Toplotna kapaciteta
0,131 J/g·K
Abundance in Earth's crust
4×10-8%
Abundance in Universe
2×10-7%
Pieces
Zasluge za slike: Images-of-elements
Pieces of pure iridium
CAS Number
7439-88-5
PubChem CID Number
23924
Atomic Properties
Atomski polmer
136 pm
Kovalentni polmer
141 pm
Elektronegativnost
2,2 (Paulingova lestvica)
Ionization Potential
8,967 eV
Atomic Volume
8,54 cm3/mol
Toplotna prevodnost
1,47 W/cm·K
Oksidacijska stanja
-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
Isotopes
Stable Isotopes
191Ir, 193Ir
Unstable Isotopes
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