PTL:Indium
From ChemEd Collaborative
Indium is a metal in Group IIIA and in period 5, between gallium (Ga) and thallium (Tl). The lighter elements in the group are boron (B) and aluminum (Al).
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Discovered
Indium was discovered in 1863 by F. Reich and his assistant H. Richter in Freiburg, German. (The work was published jointly, but Reich later regretted it because Richter tried to make it appear he was the sole discoverer.)
Name
It's name comes from the brilliant blue or indigo line its emission spectrum.
Characteristics
Indium is a very soft, lustrous, silvery-white metal. Like tin, the metal gives a sharp "cry" when it is bent. It consists of In(III) in its compounds.
Found
The element is usually found in ores rich in Zn. It is the least abundant Group IIIA element and has an abundance in the earth's crust about the same as that of silver. Nonetheless, Canada now produces more than 30 million grams per year.
Reactions
Indium metal is not oxidized by air at ordinary temperatures, but heating it to red heat produces In2O3. On heating, it also reacts directly with metalloids to give such materials as indium phosphide, which is used in lasers. The element does not react with hot water. However, it does dissolve in mineral acids. It is not affected by base. This is in sharp contrast with aluminum, which is not affected by nitric acid but does dissolve in aqueous base.
Uses
The element and its compounds find use in [bearings] for high speed/heavy duty service, in germanium [transistors], in [liquid crystal displays], and in [photocells].
Emission Spectra
This is the emission spectra for Indium.
