Ιρίδιο

77
Ir
Ομάδα
9
Περίοδος
6
Τομέας
d
Πρωτονίων
Electrons
Νετρονίων
77
77
115
General Properties
Ατομικός Αριθμός
77
Ατομικό βάρος
192,217
Mass Number
192
Κατηγορία
Στοιχεία μετάπτωσης
Χρώμα
Silver
Radioactive
Όχι
From the Latin word iris meaning rainbow
Κρυσταλλικό σύστημα
Face Centered Cubic
Ιστορία
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
Ηλεκτρονική διαμόρφωση
[Xe] 4f14 5d7 6s2
Ir
Iridium is the most corrosion-resistant metal known
Physical Properties
Phase
Στερεά
Πυκνότητα
22,56 g/cm3
Σημείο τήξης
2739,15 K | 2466 °C | 4470,8 °F
Σημείο βρασμού
4701,15 K | 4428 °C | 8002,4 °F
Heat of Fusion
26 kJ/mol
Heat of Vaporization
560 kJ/mol
Ειδική θερμοχωρητικότητα
0,131 J/g·K
Abundance in Earth's crust
4×10-8%
Abundance in Universe
2×10-7%
Pieces
Image Credits: Images-of-elements
Pieces of pure iridium
CAS Number
7439-88-5
PubChem CID Number
23924
Atomic Properties
Ατομική ακτίνα
136 pm
Ομοιοπολική ακτίνα
141 pm
Ηλεκτραρνητικότητα
2,2 (Κλίμακα Pauling)
Ionization Potential
8,967 eV
Atomic Volume
8,54 cm3/mol
Θερμική αγωγιμότητα
1,47 W/cm·K
Oxidation States
-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
Ισότοπα
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