Hydride [ Ultra HD ]

Formed when hydrogen bonds with non-metals (Groups 13–17).

Formed by many transition metals (d-block and f-block elements). hydride

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 Formed when hydrogen bonds with non-metals (Groups 13–17)

), in many hydrides, it acts as the more electronegative partner, sometimes even forming a negative anion ( H−cap H raised to the negative power they are often "non-stoichiometric

They are being heavily researched for hydrogen storage in fuel-cell vehicles because they can soak up and release hydrogen gas like a sponge.