According to de Broglie hypothesis and Heinsberg’s uncertainty principle, if and electron is to exist inside the nucleus, it should posses energy ranging from 20 MeV to 200 MeV.
But the energy of electrons emitted during ß-decay is at the most 2 to 3 MeV. Therefore, existence of electrons inside the nucleus Is not justified on the basis of wave mechanics.
(ii) The observed values of nuclear spin or angular momentum of nuclei rule out the possibility of existence of electrons inside the nucleus.
(iii) Experimentally, the values of magnetic moments of nuclei are much smaller than the magnetic moments of electrons. Therefore, electrons cannot exist inside the nucleus.
(iv) The presence of a few electrons inside the nucleus and others is revolving in orbits around the nucleus show dual role of electrons in the atomic structure, which is difficult to visualize.