Gourt > Science > Chemistry > Elements > Iridium
Iridium is a chemical element in the periodic table that has the symbol Ir and atomic number 77. A dense, very hard, brittle, silvery-white transition metal of the platinum family, iridium is used in high strength alloys that can withstand high temperatures and occurs in natural alloys with platinum or osmium. Iridium is notable for being the most corrosion resistant element known and for its association with the demise of the dinosaurs, in the form of a meteorite strike. It is used in high temperature apparatus, electrical contacts, and as a hardening agent for platinum.
Notable characteristics
A platinum group metal, iridium is white, resembling platinum, but with a slight yellowish cast. Due to its extreme hardness and brittle properties, iridium is difficult to machine, form, or work. Iridium is the most corrosion-resistant metal known. Iridium cannot be attacked by any acids or by aqua regia, but it can be attacked by molten salts, such as NaCl and NaCN.
The measured density of this element is only slightly lower than that of osmium, which is often listed as the heaviest element known. However, calculations of density from the space lattice may produce more reliable data for these elements than actual measurements and give a density of 22650 kg/m³ for iridium versus 22610 kg/m³ for osmium. Definitive selection between the two is therefore not possible at this time.
More on [ Iridium ]
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tuneko0218 (ã¤ã@22è¦ç¿ã) Tue, 29 Dec 2009 10:35:46 -0000
@iridium077 おいしそうですね（^p^）サイゼリヤですか？
@SvenAas A bright Iridium flare is visible for you at 05:51! More info: http://twiridium.appspot.com/user/25001
twiridium2 (Twiridium Bot) Tue, 29 Dec 2009 10:22:17 -0000
@SvenAas A bright Iridium flare is visible for you at 05:51! More info: http://twiridium.appspot.com/user/25001
@SvenAas A bright Iridium flare is visible for you at 05:51! More info: http://twiridium.appspot.com/user/25001
twiridium1 (Twiridium Bot) Tue, 29 Dec 2009 10:22:17 -0000
@SvenAas A bright Iridium flare is visible for you at 05:51! More info: http://twiridium.appspot.com/user/25001
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segway20 (ã»ã°ã¦ã§ã¤ã«ä¹ããã) Tue, 29 Dec 2009 10:21:54 -0000
@iridium077あれ…ゼリア？響ってきいたんやけどｗｗｗｗ
Iridium flare: magnitude -4 at 21:13:28, altitude 55°, in direction 101° (E), from Iridium 56. Weather: Partly Cloudy.
overasquith (Over Asquith) Tue, 29 Dec 2009 09:45:03 -0000
Iridium flare: magnitude -4 at 21:13:28, altitude 55°, in direction 101° (E), from Iridium 56. Weather: Partly Cloudy.
Mag -6.4 Iridium flare over Buenos Aires at 07:15 on 29/12. Will appear at 37° elevation, bearing 126° from North
overbuenosaires (Over Buenos Aires) Tue, 29 Dec 2009 08:40:13 -0000
Mag -6.4 Iridium flare over Buenos Aires at 07:15 on 29/12. Will appear at 37° elevation, bearing 126° from North
ChemGlobe: Iridium - Electronic, thermal, and steric data along with an isotope table.
Meta Description: [ The chemical element [Ir] - Iridium - Datasheet ]
ChemicalElements.com: Iridium - Basic information, atomic structure, and table of isotopes.
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EnvironmentalChemistry.com: Iridium - Atomic structure, chemical and physical properties, and table of nuclides.
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Iridium - Data tables and historic information.
It's Elemental: Iridium - Basic physical and historical information.
Meta Description: [ The Element Iridium - Basic Physical and Historical Information ]
LANL: Iridium - History, properties, uses, and sources.
Lenntech: Iridium - Physical data, chemical properties, health and environmental effects.
Meta Description: [ chemical properties, health and environmental effects of iridium ]
Radiochemistry of Iridium - Full text of the monograph by G. W. Leddicotte (Oak Ridge National Laboratory, Oak Ridge, Tennessee). [PDF]
Visual Elements: Iridium - Image, general and physical information, source, uses, key isotopes, and ionisation energies.
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WebElements: Iridium - Extensive information on history, uses, occurrence, compounds, and properties.
Meta Description: [ This WebElements periodic table page contains key information for the element iridium ]
Wikipedia: Iridium - Properties of the element, including its history, applications, and characteristics.
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