Question

Assertion: atomic number is equal to number of protons only in Case of ions.
Reason: atomic number is equal to number of protons or electrons even in an ion

Answer 1

Answer:

Atomic number is a more fundamental property of an element than its atomic mass. On arranging elements in the increasing order of their atomic numbers, similarities appear in physical and chemical properties at regular intervals.

Atomic number is equal to number of protons in an atom. It is also equal to the number of electrons.

both A and R is correct but R isn't the correct explanation of A