Why is the hydride ion a strong base?

The hydride ion ($H^{-}$) is considered a strong base because it has a high tendency to accept a proton ($H^{+}$) to form a stable molecule.12

Under the Brønsted–Lowry definition, a base is defined as a species that acts as a proton acceptor. In the case of saline (ionic) hydrides, the hydride ion reacts instantly and quantitatively with the hydrogen ion from water to produce hydrogen gas and the hydroxide ion:12

$$H^{-}+H_{2}O\to H_2+O{H}^{-}$$

This vigorous reaction demonstrates the strong basicity of the hydride ion, as it effectively strips a proton from water molecules. While all hydrogen compounds can formally be defined as acids or bases depending on their tendency to lose or gain a proton, the hydride ion’s significant electron density and its role as a potent proton acceptor distinguish it as a strong base in chemical systems.21