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

Hydrogen gains an electron to achieve the configuration of a noble gas. It behaves like which of the following?

Which of the following statement$(s)$ is/are correct:
$A$. $NaH$ is a non-volatile hydride
$B$. $MgH_2$ is a polymeric hydride
$C$. $NH_3$ is an electron-precise hydride
$D$. $H_2O$ is an electron-rich hydride

Among the following,the correct statements are:
$I$. $LiH, BeH_2$ and $MgH_2$ are saline hydrides with significant covalent character.
$II$. Saline hydrides are volatile.
$III$. Electron-precise hydrides are Lewis bases.
$IV$. The formula for chromium hydride is $CrH$.
The correct option is:

Which of the following statements is not true for hydrogen:
$1)$ It exists as a diatomic molecule.
$2)$ It has one electron in the outermost shell.
$3)$ It can lose an electron to form a cation which can freely exist.
$4)$ It cannot form ionic compounds.

Which property among the following is the same for both hydrogen and deuterium molecules?