Question

In isoelectronic species, Cl⁻, Ar, Ca²⁺ sizes differ due to

• A. Nuclear charge
• B. Electronic – electronic repulsion in valence shell
• C. Magnetic quantum number
• D. Principal quantum number

Answer 1

The correct option is A

Nuclear charge

Solution: Option (A)- Nuclear charge

• In isoelectronic nature, they all had the same number of electrons in the respective atom/ion/molecule.
• Due to the difference in their atomic number their position/arrangement in the periodic table is different.
• So, they feel different nuclear attractions according to their positions.
• Therefore, their size will be different compared to each other.

So, the correct answer is option A.