Constituents of the Nucleus :
i) Proton -Electron Hypothesis:-
a) Nuclear Size:
Nuclei are only of the order of 10^-15 m. According to the Uncertainty principle
b) Nuclear Magnetic Moment :
c) Nuclear Spin :
ii) Proton -Neutron Hypothesis :
The hypothesis that nuclei are composed of protons & neutron explains the existence of isotopes.