Identify the correct statements from the following:
$I$. $B_2H_6$ is an electron deficient hydride.
$II$. $NH_3$ is an electron rich hydride.
$III$. $NaH$ is a covalent hydride.
$IV$. $YbH_{2.55}$ is an interstitial hydride.

Match List-$I$ with List-$II$

List-$I$ Type of Hydride	List-$II$ Example
$A$. Electron deficient hydride	$I$. $MgH_2$
$B$. Electron rich hydride	$II$. $HF$
$C$. Electron precise hydride	$III$. $B_2H_6$
$D$. Saline hydride	$IV$. $CH_4$

Choose the correct answer from the options given below:

Which of the following will not be reduced by $H_2$?

What happens when ionic hydrides of $s$-block elements in molten state are electrolysed?

Identify the correct statements about the hydrides.
$(I)$ In saline hydrides,the oxidation state of hydrogen is $-1$.
$(II)$ $LaH_{2.87}$ is an example of an interstitial hydride.
$(III)$ $NH_3$ and $H_2O$ have the tendency to form hydrogen bonds.
$(IV)$ Electrolysis of molten sodium hydride liberates $H_2$ gas at the anode.

Deuterium resembles hydrogen in chemical properties but reacts: