Question

Why the size of an anion is larger than its parent atom?

Answer 1

Cations are smaller in sizebecause they are formed by loss of electrons and anions are largerin size because they are formed by the gain of electrons. cationthan in its parent atom. Therefore, a cation is smaller insize than its parent atom.

Answer 2

Answer:

(1) An anion is formed by the acceptance of an electron by a parent atom.

A + e^- → A^-

(2) The nuclear charge in a parent atom and its anion is same.

(3) The additional electron in an anion, results in the repulsion among the electrons and results in the decrease in effective nuclear charge, as compared to the parent atom. Therefore, the radius of an anion is larger than its parent atom. For example, F atom has atomic radius 64 pm while anion F has ionic radius 136 pm