Question

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Radius of H⁺ is 1.5 × 10^–3 pm
Reason (R) : H⁺ cannot exist independently
In the light of the above statements, write the detailed answer:

Answer 1

Analysis of Assertion (A):

• The hydrogen ion (H⁺) is essentially a proton.
• Since a proton is a subatomic particle with an extremely small size, its radius is approximately 1.5 × 10^–3 pm.
• Thus, the Assertion (A) is correct.

Analysis of Reason (R):

• H⁺ is a bare proton without any electrons. Due to its high charge density and extremely small size, it cannot exist independently in nature.
• Instead, it immediately associates with other atoms or molecules, typically forming complexes like H₃O⁺ in aqueous solutions.
• Thus, the Reason (R) is also correct.

Conclusion:

Both the Assertion (A) and Reason (R) are correct. Furthermore, the Reason (R) correctly explains the Assertion (A). Therefore, the correct answer is:

Option A: Both A and R are true, and R is the correct explanation of A.