They are generally grouped into three categories based on the type of chemical bond involved: 1. Ionic (Saline) Hydrides
Hydrogen atoms occupy the small holes (interstices) in the metal's crystal lattice. hydride
Formed when hydrogen reacts with highly reactive alkali metals (Group 1) or alkaline earth metals (Group 2, like Calcium). They are generally grouped into three categories based
Not enough electrons to form conventional bonds (e.g., B2H6cap B sub 2 cap H sub 6 Electron-precise: Perfect match of electrons (e.g., CH4cap C cap H sub 4 - Methane). Electron-rich: Have "lone pairs" of electrons (e.g., NH3cap N cap H sub 3 - Ammonia, or H2Ocap H sub 2 cap O 3. Metallic (Interstitial) Hydrides Not enough electrons to form conventional bonds (e
They often retain metallic properties like luster and conductivity. Interestingly, they are often "non-stoichiometric," meaning the ratio of hydrogen to metal isn't a fixed whole number (e.g., LaH2.87cap L a cap H sub 2.87