Difference between revisions of "Iridium"
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'''Iridium''' is an [[element]] in the [[transition metal]]s class of the [[periodic table of the elements|periodic table]]. It is hard and lustrous, and is perhaps the most corrosion-resistant metal known. It has the second-highest density of all elements, after [[osmium]]. | '''Iridium''' is an [[element]] in the [[transition metal]]s class of the [[periodic table of the elements|periodic table]]. It is hard and lustrous, and is perhaps the most corrosion-resistant metal known. It has the second-highest density of all elements, after [[osmium]]. | ||
| − | An alloy of [[platinum]] and iridium was used in the international standard [[International_System_of_Units#Meter|meter]] bar, before the standard was changed in 1960. A similar alloy is still used in the international standard [[International_System_of_Units#Kilogram|kilogram]]. An alloy of 90% platinum and 10% iridium is widely used in both the jewelry and chemical industries, because it is strong, hard, beautiful, and impervious to almost all chemicals even at very high temperatures. | + | An alloy of [[platinum]] and iridium was used in the international standard [[International_System_of_Units#Meter|meter]] bar, before the standard was changed in 1960. A similar alloy is still used in the international standard [[International_System_of_Units#Kilogram|kilogram]]. An alloy of 90% [[platinum]] and 10% iridium is widely used in both the jewelry and chemical industries, because it is strong, hard, beautiful, and impervious to almost all chemicals even at very high temperatures. |
== Uses == | == Uses == | ||
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- Phonograph needles. | - Phonograph needles. | ||
| − | - It forms an alloy with osmium used for tipping pens and compass bearings. | + | - It forms an alloy with [[osmium]] used for tipping pens and compass bearings. |
- Electrical contacts. | - Electrical contacts. | ||
[[Category:Elements]] | [[Category:Elements]] | ||
Revision as of 23:15, March 23, 2009
| Iridium | |
|---|---|
| Properties | |
| Atomic symbol | Ir |
| Atomic number | 77 |
| Classification | Transition Metals |
| Atomic mass | 192.22 amu |
| Number of Stable Isotopes | 2 |
| Density (grams per cc) | 22.560 g/cm^3 |
| Other Information | |
| Date of discovery | 1803 |
| Name of discoverer | Smithson Tennant |
| Name origin | From the Latin iridis, meaning rainbow. |
| Uses | Used in conjunction with osmium to tip gold pen points, to make crucibles and other high-temperature containers. Also used to make alloys for standard weights and measures, as well as heat-resistant alloys. In addition, used in cancer irradiation, hypodermic needles, helicopter spark plugs and as hardening agent for platinum. |
| Obtained from | Found in gravel deposits with platinum, iridosmium, and osmiridium ores. |
Iridium is an element in the transition metals class of the periodic table. It is hard and lustrous, and is perhaps the most corrosion-resistant metal known. It has the second-highest density of all elements, after osmium.
An alloy of platinum and iridium was used in the international standard meter bar, before the standard was changed in 1960. A similar alloy is still used in the international standard kilogram. An alloy of 90% platinum and 10% iridium is widely used in both the jewelry and chemical industries, because it is strong, hard, beautiful, and impervious to almost all chemicals even at very high temperatures.
Uses
Iridium does not have many "everyday" uses, but a few common ones are:
- Spark plugs.
- Phonograph needles.
- It forms an alloy with osmium used for tipping pens and compass bearings.
- Electrical contacts.