Hydrogen from $HCl$ can be prepared by

The shape of the colourless neutral gas formed on thermal decomposition of ammonium nitrate is

Which of the following metals is capable of occluding hydrogen?

State True or False for the following statements:
$1$. Metals of group $7$,$8$ and $9$ form non-stoichiometric hydrides.
$2$. Pure dihydrogen is obtained by heating hydrocarbons with $H_2O$ vapour in the presence of a $Ni$ catalyst at $1270 \ K$.
$3$. The ionization enthalpy of hydrogen is higher than that of alkali metals.
$4$. Some chemical properties of hydrogen resemble both metals and non-metals.

Out of the two allotropic forms of dihydrogen,the form with lesser molecular energy is

Ordinary hydrogen at room temperature is a mixture of