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For transistors. | Atomic Number: | 49 | Atomic Symbol: | In | | Atomic Weight: | 114.82 | Electron Configuration: | 2-8-18-18-3 | | Shells: | 2,8,18,18,3 | Filling Orbital: | 5p1 | | Melting Point: | 156.61oC | Boiling Point: | 2000oC | | Description: | Rare silver-white metal | | Uses: | Used to coat high speed bearings |
History(from the brilliant indigo line in its spectrum) Discovered by
Reich and Richter, who later isolated the metal. Indium is most frequently
associated with zinc materials, and it is from these that most commercial indium
is now obtained; however, it is also found in iron, lead, and copper ores. Until
1924, a gram or so constituted the world's supply of this element in isolated
form. It is probably about as abundant as silver. About 4 million troy ounces of
indium are now produced annually in the Free World. Canada is presently
producing more than 1,000,000 troy ounces annually. The present cost of indium
is about $1 to $5/g, depending on quantity and purity. It is available in
ultrapure form.
Properties- Indium is a very soft, silvery-white metal with a brilliant luster.
- The pure metal gives a high-pitched "cry" when bent.
- It wets glass, as does gallium.
Uses- It has found application in making low-melting allows; an alloy of 24%
indium - 76% gallium is liquid at room temperature.
- It is used in making bearing alloys, germanium transistors, rectifiers,
thermistors, and photoconductors.
- It can be plated onto metal and evaporated onto glass, forming a mirror as
good as that made with silver but with more resistance to atmospheric corrosion.
HandlingThere is evidence that indium has a low order of toxicity;
however, care should be taken until further information is available.
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