Heavy stable nucleus have more neutrons than protons. This is because of the fact that

Options

A. neutrons are heavier than protons
B. electrostatic force between protons are repulsive.
C. neutrons decay into protons through beta decay.
D. nuclear forces between neutrons are weaker than that between protons.

Answer

B

Explanation

Electrostatic force between proton-proton is repulsive which causes the instability of nucleus. So neutrons are more than the number of protons.