Question

Why is the atomic mass not the mass of neutrons and protons and why is it the no. of neutrons and protons

Answer 1

THE ANSWER OF THIS QUESTION IS :

So atomic mass is not double of the atomic number... It usually is because the atomic number describes how many protons there are in an atom's nucleus and the atomic mass is the total mass of all protons, neutrons and electrons. However, the mass of an electron is so small as to be relatively insignificant.