Editing Alkali metal (section)

==== Lithium ====
The chemistry of lithium shows several differences from that of the rest of the group as the small Li<sup>+</sup> cation [[chemical polarity|polarises]] [[anion]]s and gives its compounds a more [[covalent]] character.<ref name=rsc /> Lithium and [[magnesium]] have a [[diagonal relationship]] due to their similar atomic radii,<ref name=rsc /> so that they show some similarities. For example, lithium forms a stable [[nitride]], a property common among all the [[alkaline earth metal]]s (magnesium's group) but unique among the alkali metals.<ref name="alkalireact" /> In addition, among their respective groups, only lithium and magnesium form [[organometallic compound]]s with significant covalent character (e.g. Li[[methyl group|Me]] and MgMe<sub>2</sub>).<ref name="Shriver&Atkins">{{cite book |title=Inorganic Chemistry |first1=Duward |last1=Shriver |first2=Peter |last2=Atkins |publisher=W. H. Freeman |year=2006 |isbn=978-0-7167-4878-6 |page=259 |access-date=10 November 2012 |url=https://books.google.com/books?id=NwOTQAAACAAJ }}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

Lithium fluoride is the only alkali metal halide that is poorly soluble in water,<ref name=rsc /> and [[lithium hydroxide]] is the only alkali metal hydroxide that is not [[deliquescent]].<ref name=rsc /> Conversely, [[lithium perchlorate]] and other lithium salts with large anions that cannot be polarised are much more stable than the analogous compounds of the other alkali metals, probably because Li<sup>+</sup> has a high [[solvation energy]].<ref name="Greenwood&Earnshaw" />{{rp|76}} This effect also means that most simple lithium salts are commonly encountered in hydrated form, because the anhydrous forms are extremely [[hygroscopic]]: this allows salts like [[lithium chloride]] and [[lithium bromide]] to be used in [[dehumidifier]]s and [[air-conditioner]]s.<ref name="Greenwood&Earnshaw" />{{rp|76}}