Hydrogen Forms Metallic (Interstitial) Hydrides with the D and F

Multiple Choice

Hydrogen forms metallic (interstitial) hydrides with the d and f transition elements. Which of the following statements is correct?

A) These substances have distinct stoichiometric formulas like ionic hydrides.
B) Hydrogen forms bonds with the metals by donating its electron to the valence band of the metal.
C) Hydrogen molecules and atoms occupy holes within the crystal structure of the metal.
D) These substances are useful catalysts.
E) These hydrides are stabilized by hydrogen bonding forces.