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

We need to evaluate the Assertion and Reason about hydrogen as a fuel.

Assertion A: "Hydrogen is an environment friendly fuel."

This is TRUE. When hydrogen burns in air, the only product is water: $$2H_2 + O_2 \rightarrow 2H_2O$$. No pollutants like CO$$_2$$, SO$$_2$$, or NOx are produced, making it environmentally friendly.

Reason R: "Hydrogen has the atomic number 1 and it is the lightest element."

This is TRUE as a factual statement. Hydrogen has atomic number 1 and is indeed the lightest element in the periodic table.

However, the reason R does not explain why hydrogen is an environmentally friendly fuel. The environmental friendliness comes from the fact that its combustion product is water (not harmful gases), not from the fact that it has atomic number 1 or is lightweight.

The correct answer is Option (2): Both A and R are true but R is NOT the correct explanation of A.