The nucleus of tritium contains

Given below are two statements:
Assertion $(A)$: Protium and deuterium differ in their rates of reactions.
Reason $(R)$: They have different enthalpies of bond dissociation.
The correct answer is:

Hydrogen does not combine with

Hydrogen gas will not reduce

Under what conditions can hydrogen behave as a metal?

Which of the following upon hydrolysis can produce a hydrocarbon that has the same degree of unsaturation as the number of carbon atoms present in the produced hydrocarbon?