Question

What effect is observed, on the size of an atom when an electron is removed and in another case an electron is added to the same atom?

(a) Size increases and decreases respectively

(b) Size decreases and increases respectively

(c) Size increases in both cases

(d) Size decreases in both cases

Answer 1

(b) Size decreases and increases respectively

When an atom loses an electron, it forms a cation. The atomic radius is larger than the ionic radius. The nuclear charge remains the same but the number of electrons decreases by 1. Hence, the effective nuclear charge per electron increases.