hydride (redirected from Hydrides)

hydride

Any of a class of compounds in which hydrogen is combined with another element. There are three basic types of hydrides: saline, metallic, and covalent. Saline hydrides, such as sodium hydride (NaH) and calcium hydride (CaH₂), are often used as portable sources of hydrogen gas (H₂). Metallic hydrides, such as titanium hydride (TiH₂), are alloylike materials (see alloy) with some properties of metals, such as lustre and electrical conductivity. Covalent hydrides (see covalent bond) are mostly compounds of hydrogen and nonmetallic elements; they include water, ammonia, hydrogen sulfide (H₂S), and methane. A fourth group of hydrides, dimeric (polymeric) hydrides, is sometimes recognized (see borane). Dimeric hydrides give off large amounts of energy when burned and may be useful as rocket fuels.