Iridium [Ir] (CAS-ID: 7439-88-5) |
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An: 77 N: 115 Am: 192.217 (3) |
Group No: 9
Group Name: Precious metal or Platinum group metal
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Block: d-block
Period: 6
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State: solid at 298 K |
Colour: silvery white Classification: Metallic |
Boiling Point: 4701K (4428'C) |
Melting Point: 2719K (2446'C) |
Density: 22.65g/cm3 |
Availability: Iridium is available in many forms including foil, sheet, wire, "evaporation slugs", powder, and sponge. |
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Discovery Information |
Who:
Smithson Tenant
, A.F.Fourcory,
L.N.Vauquelin
, H.V.Collet-Descoltils |
When: 1804 |
Where: England/France |
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Name Origin |
Latin: iris, iridis (rainbow) as many of its salts are stronly coloured. |
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Sources |
Found in gravel deposits with platinum. Naturally ocurring iridium alloys include iridiosmium and osmiridium, both of which are mixtures of iridium and osmium. Although rare on Earth, iridium is common in meteorites. |
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Uses |
Used with osmium to tip gold pen points, to make crucible and special containers (that require high temperature resistance). Used to make alloys used for standard weights and measures, and heat-resistant alloys. Also used incancer irradiation, hypodermic needles, helicopter spark plugs and as hardening agent for platinum. |
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Notes |
Iridium is notable for being the most corrosion resistant element known. |
Iridium metal is generally non-toxic, but it's compounds should be regarded as highly toxic. |