What is Hydrides?

A hydride is a binary compound of hydrogen with another element. Saline hydrides, formed with the alkali and heavier alkaline-earth metals ($\ce{LiH}$, $\ce{NaH}$, $\ce{CaH2}$), are ionic solids containing $\ce{H-}$. Covalent hydrides, formed with the p-block elements ($\ce{CH4}$, $\ce{NH3}$, $\ce{H2O}$, $\ce{HCl}$), are molecular. Metallic hydrides, formed with some transition metals, are solids in which hydrogen occupies interstitial sites of the metal lattice, often with a variable composition.