Question

why anions are greater then parent atom

Answer 1

Answer:

anions have more electron by which    number   of orbits may increase and  overall size of orbital increases   .so,their size is greater than parent atom

Explanation:

Answer 2

Anions are greater than their parent atom because the parent atom has equal number of protons and electrons and anions are formed by accepting the electrons , so number of electrons will be greater than protons, then, effective nuclear charge decreases and size increases.