Novel inorganic alkali and alkaline earth hydrides of the f o r m u l a MH *, MH 2 * , and MH X * wherein M is the metal, X , is a halide, and H * comprises a novel high binding energy hydride ion were synthesized in a high temperature gas cell by reaction of atomic hydrogen with a catalyst and MH , MH 2 , or MX corresponding to an alkali metal or alkaline e a r t h metal compound, respectively...