Identify the reaction which does not liberate hydrogen.

If a mole of $H_2$ molecules is heated to a high temperature,which of the following reactions takes place?

Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

With which of the following does hydrogen combine directly?

Which of the following is not an isotope of hydrogen?

Identify the correct statements from the following.
$(i)$ The number of hydrogen bonded water molecules in copper sulphate pentahydrate is one.
$(ii)$ Lanthanum and zirconium form non-stoichiometric hydrides.
$(iii)$ In solid form of $H_2O$, each oxygen is surrounded by six oxygen in octahedral positions at a distance of $276 \ pm$.