The chemical formula of barium hydride is BaH2. Ba is the chemical symbol for barium, and H is the chemical symbol for hydrogen. The 2 after the H indicates the molecule contains two atoms of hydrogen, while the absence of a number after the Ba indicates one atom of barium.
Barium hydride can be formed by combining a barium ion with a charge of +2 with two hydrogen atoms, each with a charge of -1. When combined, the charges cancel one another out, leaving a compound with a neutral charge. The molecular mass of barium hydride is 139.34 grams per mole.