The comments above are all lacking a very essential aspect:
The kinetic energy of the electron which never will become zero,
is the reason for some sort of repulsive force near the nucleus.
This is very often overlooked and may also be explained by the
the De Broglie wavelength.
By the...
May I correct this: the charge of an electron is -e, the charge of a proton ist +e!
Thus the Coulomb force between the two e.g. in a H atom is proportional to
q1*q2 = (-e)*(+e) = - e2.
Z then simply is the number of protons in a nucleus of other atoms.
B.K.
May I correct this: the charge of an electron is -e, the charge of a proton ist +e!
Thus the Force between the two is proportional to q1*q2, or (-e)*(+e) = - e2
B.K.