Indium

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Indium

This is indium.

Symbol In
Atomic number 49
Atomic mass 114.82 amu

Indium is a rare metal, discovered in 1863.

Distinguishing properties

Indium is characterized as a soft and malleable, silvery-white metal. It looks like aluminum, but resembles tin when being bent. Indium is soft that it rubs onto other objects in much the same way as graphite and pencil lead. Pure indium can be polished and it will retain its shine as it is corrosion resistant.

Occurrence

Indium is found as a trace element in zinc and lead sulfide ores. Therefore, zinc refineries are the world's major source of indium. Over a thousand kilograms of indium are recovered each year from the flue dust of zinc refineries.

Usage

Indium is used mostly for electroplating steel bearings. It is used in sprinklers as an alloy as it lowers the melting point of other metals. This low melting point contributes to its commercial value as an alloying agent for soldering material. Relatively small amounts are used in dental items and in semiconductors with phosphorus. Long-lived indium battery has also been devised to power electronic wrist watches.

See also

Periodic table of the elements