Hydrogen accepts an electron to form an inert gas configuration. In this property,it resembles:

Assertion : Sulphuric acid is more viscous than water.
Reason : Concentrated sulphuric acid has a great affinity for water.

Calcium imide on hydrolysis will give gas $(B)$ which on oxidation by bleaching powder gives gas $(C)$. Gas $(C)$ on reaction with magnesium gives compound $(D)$. $(D)$ on hydrolysis gives again gas $(B)$. $(B)$,$(C)$ and $(D)$ are

How many isotopes of Hydrogen are there? Give their names.

Hydrogen accepts an electron to achieve the inert gas configuration. In this process,it behaves like which of the following?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : Hydrogen is the most abundant element in the Universe,but it is not the most abundant gas in the troposphere.
Reason $R$ : Hydrogen is the lightest element.
In the light of the above statements,choose the correct answer from the options given below: