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

Select the correct statement regarding interstitial hydrides.

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

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: Loss of electron from hydrogen atom results in a nucleus of $\sim 1.5 \times 10^{-3} \ pm$ size.
Reason $(R)$: Proton $(H^+)$ always exists in combined form.
In the light of the above statements,choose the most appropriate answer from the options given below:

Ionisation of $H$-atom would produce

Identify the catalyst used in the following reaction: $CO_{(g)} + H_2O_{(g)} \xrightarrow{623 \ K} CO_{2_{(g)}} + H_{2_{(g)}}$