Given two statements below:
Statement I: In $$Cl_2$$ 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

We need to evaluate two statements about atomic and ionic radii.

Statement I: In Cl₂ molecule, the covalent radius is double the atomic radius of chlorine.

This statement is incorrect. In fact, the covalent radius is half the internuclear distance in a Cl₂ molecule. The atomic radius (van der Waals radius) of chlorine is always greater than its covalent radius. The covalent radius of Cl is approximately 99 pm, while its van der Waals radius is about 175 pm. So the covalent radius is NOT double the atomic radius; rather, the covalent radius is less than the atomic radius.

Statement II: Radius of anionic species is always greater than their parent atomic radius.

This statement is correct. When an atom gains electrons to form an anion, the increased electron-electron repulsion causes the electron cloud to expand. Additionally, the same nuclear charge now holds more electrons, leading to a decreased effective nuclear charge per electron. Therefore, anions are always larger than their parent atoms.

For example:

• Cl atom: 99 pm (covalent radius)
• Cl⁻ ion: 181 pm
• O atom: 73 pm
• O²⁻ ion: 140 pm

Since Statement I is incorrect and Statement II is correct, the answer is Option D.