Question

In an atom number of protons is equal to number of neutrons. Then why we don’t use electrons as a bases to define atomic number and atomic mass?

Answer 1

Answer:

we don't use electrons as atomic number because in most elements electrons can easily move from one atom to another atom hence their number may change but removing proton from atom is very so we use it as atomic number.

And we don't use it as atomic mass because they are very small in compare to proton as 1 proton mass is about 1000 times more than electron so we neglect electron mass