Question

From mass number how to calculate electrons and neutrons

Answer 1

The no. Of electrons can't be calculated by mass of element but it is equal to the atomic no. and no. Of neutrons is equal to difference between the atomic mass and the atomic number of the element. E.g. I the case of helium, at. No. = 2 and at. mass = 4
Therefore, no. of protons = at no. = 2
No. Of electrons = at no. = 2
No. Of neutrons = at mass - at.
No.
= 4 - 2 = 2
This implies, no. Of neutrons = 2