Question

Why mass of electrons is not consider in the atomic mass of an atom?

Answer 1

All atoms have atleast one proton in their core and the number of protons determine the kind of element of an atom.Electrons are usually smaller than protons and neutrons because their mass is so much smaller .
Electron mass is so small thats why it is not counted in atom's mass.
I hope it will help u...

Answer 2

Answer: The mass of electron is negligible (9.1× 10^-28)...hence it is not considered in the atimic mass..