Editing Indium (section)

===Indium(III)===
[[File:Kristallstruktur Chrom(III)-chlorid.png|thumb|right|upright=1|[[Indium trichloride|InCl<sub>3</sub>]] ''(structure pictured)'' is a common compound of indium.]]
[[Indium(III) oxide]], In<sub>2</sub>O<sub>3</sub>, forms when indium metal is burned in air or when the hydroxide or nitrate is heated.<ref name="downs">{{Cite book| title = Chemistry of aluminium, gallium, indium, and thallium| author = Anthony John Downs| publisher = Springer| year = 1993| isbn = 978-0-7514-0103-5}}</ref> In<sub>2</sub>O<sub>3</sub> adopts a structure like [[alumina]] and is amphoteric, that is able to react with both acids and bases. Indium reacts with water to reproduce soluble [[indium(III) hydroxide]], which is also amphoteric; with alkalis to produce indates(III); and with acids to produce indium(III) salts:

:In(OH)<sub>3</sub> + 3&nbsp;HCl → InCl<sub>3</sub> + 3&nbsp;H<sub>2</sub>O

The analogous sesqui-chalcogenides with [[sulfur]], [[selenium]], and [[tellurium]] are also known.<ref name="Greenwood286">Greenwood and Earnshaw, p. 286</ref> Indium forms the expected [[indium halides|trihalides]]. Chlorination, bromination, and iodination of In produce colorless [[indium(III) chloride|InCl<sub>3</sub>]], [[indium(III) bromide|InBr<sub>3</sub>]], and yellow InI<sub>3</sub>. The compounds are [[Lewis acid]]s, somewhat akin to the better known aluminium trihalides. Again like the related aluminium compound, InF<sub>3</sub> is polymeric.<ref name="Greenwood263">Greenwood and Earnshaw, pp. 263–7</ref>

Direct reaction of indium with the [[pnictogen]]s produces the gray or semimetallic III–V [[semiconductor]]s. Many of them slowly decompose in moist air, necessitating careful storage of semiconductor compounds to prevent contact with the atmosphere. Indium nitride is readily attacked by acids and alkalis.<ref name="Greenwood288">Greenwood and Earnshaw, p. 288</ref>