Given two statements below :
Statement I : In Cl₂ molecule the covalent radius is double of the atomic radius of chlorine.
Statement II : Radius of anionic species is always greater than their parent atomic radius.
Choose the most appropriate answer from options given below :

Solution

Chemistry ma’am · 4 steps

The bond length is double the radius, not the radius itself. And extra electrons always puff an anion up.

1. What covalent radius means. For a non-metal like chlorine, the atomic radius is measured as the covalent radius. It is half the distance between the two nuclei in Cl₂.

   r_(cov)(Cl) = d_(Cl-Cl)/2 = (198 pm)/2 = 99 pm

2. Statement I. The internuclear distance (198 pm) is double the radius, but the covalent radius itself is the atomic radius of chlorine, 99 pm. Calling it double the atomic radius is incorrect.
3. Statement II. An anion has more electrons than its parent atom but the same nuclear charge. Each electron feels a smaller pull and the electrons repel each other more, so the cloud spreads out. For example, Cl is 99 pm and Cl⁻ is 181 pm. The statement is correct.
4. So. Statement I is incorrect and Statement II is correct, which is option (d).

The idea to keep. Bond length between two identical atoms is twice the covalent radius. Adding electrons always makes the species bigger, and removing electrons always makes it smaller.

Answer from the NTA final answer key. Solution by PrepWiser.