Hydrogen can be placed in the halogen group because

Which of the following is obtained when dihydrogen reacts with the alkali metals at high temperature?

Identify the catalyst used in the following reaction at $500^{\circ} C$:
$CO + H_2O \rightleftharpoons CO_2 + H_2$

Which type of ions are present in the anhydrous mixture of $KF$ and $HF$?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Physical properties of isotopes of hydrogen are different.
Reason $R$: Mass difference between isotopes of hydrogen is very large.
In the light of the above statements,choose the correct answer from the options given below:

Given below are two statements :
Statement-$I$: Methane and steam passed over a heated $Ni$ catalyst produces hydrogen gas.
Statement-$II$: Sodium nitrite reacts with $NH_4Cl$ to give $H_2O$,$N_2$ and $NaCl$.
In the light of the above statements,choose the most appropriate answer from the options given below :