Hydride

In chemistry, a hydride is the anion of hydrogen, H−, or, more commonly, a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, hydrogen is bonded to a more electropositive element or group. Compounds containing metal or metalloid bonds to hydrogen are often referred to as hydrides, even though these hydrogen centres can have a protic character. Almost all of the elements form binary compounds with hydrogen, the exceptions being He, Kr, Tc, Ru, Pm, Os, Ir, Rn, Fr, Ra, Ac, Pa.