Question

why cations are smaller and anion larger in size than their parent atom

Answer 1

Cations are always smaller than their parent atoms this is because they have lesser electrons, while their nuclear charge remains the same. The remaining electrons are, therefore held more tightly by the protons in the nucleus and thus their radii.are smaller than the parent atoms. This is opposite in case of anions.

Answer 2

1. because cation means loose an electron from an atom for ex calcium have 20 electrons and calcium2positive have 18 electrons so thats why cations are smaller in size than their parent atom.

2. because anion means addition of electron in an atom for ex chlorine have 17 electron and chlorine1negative have 18 electron so thats why anion are larger in size than there parent atom.