A hydride is a compound formed by the combination of hydrogen and another element. The hydrogen atom in a hydride typically has a negative oxidation state.

Water (H₂O) is not a hydride because the hydrogen atoms in water have a positive oxidation state.

The general formula of a binary hydride is MH_n, where M is the symbol of the other element and n is the number of hydrogen atoms in the compound.

Hydrogen sulfide (H₂S) is a gas at room temperature. The other hydrides listed are solids.

Water (H₂O) is a liquid at room temperature. The other hydrides listed are solids.

Sodium hydride (NaH) is a solid at room temperature. The other hydrides listed are gases or liquids.

Binary hydrides are the most common type of hydride. They are formed by the combination of hydrogen and another element.

Lithium aluminum hydride (LiAlH₄) is an example of a complex hydride. It is formed by the combination of lithium, aluminum, and hydrogen.

Lanthanum nickel hydride (LaNi₅H₆) is an example of an intermetallic hydride. It is formed by the combination of lanthanum, nickel, and hydrogen.

Sodium borohydride (NaBH₄) is an example of a saline hydride. It is formed by the combination of sodium, boron, and hydrogen.

Hydrides are generally highly reactive, have low melting and boiling points, and are good reducing agents.

Hydrides are used as fuel sources, in the production of hydrogen, and as reducing agents in chemical reactions.

Hydrogen sulfide (H₂S) is used in the production of sulfuric acid.

Sodium borohydride (NaBH₄) is used as a reducing agent in chemical reactions.

Lithium aluminum hydride (LiAlH₄) is used as a reducing agent in chemical reactions.