When $NaBH_4$ is dissolved in water,

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ Hydrogen is an environment-friendly fuel.
Reason $R:$ Atomic number of hydrogen is $1$ and it is a very light element.
In the light of the above statements,choose the correct answer from the options given below:

Pick out the correct statement regarding the conversion of ortho and para hydrogen.

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.

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

Exhausted permutit does not contain ....... ion.