Iridium

77
Ir
Golongan
9
Periode
6
Blok
d
Proton
Elektron
Neutron
77
77
115
Sifat Umum
Nomor atom
77
Massa atom
192,217
Nomor massa
192
Kategori
Logam transisi
Warna
Perak
Radioaktif
Tidak
From the Latin word iris meaning rainbow
Struktur kristal
Kubik Berpusat-muka
Sejarah
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.
Elektron per kulit
2, 8, 18, 32, 15, 2
Konfigurasi elektron
[Xe] 4f14 5d7 6s2
Ir
Iridium is the most corrosion-resistant metal known
Sifat Fisika
Fase
Solid
Kepadatan
22,56 g/cm3
Titik lebur
2739,15 K | 2466 °C | 4470,8 °F
Titik didih
4701,15 K | 4428 °C | 8002,4 °F
Kalor peleburan
26 kJ/mol
Kalor penguapan
560 kJ/mol
Kapasitas kalor molar
0,131 J/g·K
Kelimpahan di kerak bumi
4×10-8%
Kelimpahan di alam semesta
2×10-7%
Pieces
Kredit Gambar: Images-of-elements
Pieces of pure iridium
Nomor CAS
7439-88-5
PubChem CID Number
23924
Sifat Atom
Jari-jari atom
136 pm
Jari-jari kovalen
141 pm
Elektronegativitas
2,2 (Skala Pauling)
Potensi Ionisasi
8,967 eV
Volume atom
8,54 cm3/mol
Kondusivitas termal
1,47 W/cm·K
Bilangan oksidasi
-3, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9
Aplikasi
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
Isotop
Isotop stabil
191Ir, 193Ir
Isotop tidak stabil
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