Question

What are interstitial hydrides?

Answer 1

Interstitial hydrides are called as such, because in these compounds, hydrogen occupies interstitial sites in the metal lattice without changing the type of the lattice. Many d-block and f-block elements (except group 7, 8, and 9) form these hydrides (only Cr of group 6 forms CrH). Interstitial hydrides are called as non-stoichiometric compounds also.
example of stoichiometric compounds 

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Answer 2

Answer:

See the above attachment