In an atom what stops the electrons from being pulled into the nucleus due to electrostatic attraction? Why are electrons able to stay in orbits without being flung off?
This was a “killer blow” for the idea of a nuclear atom until it was discovered by Neils Bohr that energy states in atoms are quantised.
He showed that electron energies are not continuous in atoms, but are discrete or quantised states (as evidenced by emission and absorption spectra in pure gases.)
This meant that electrons could not gradually radiate away energy and spiral into the nucleus under the influence of electrostatic attraction, but were held rigidly in infinitely thin ‘shells’.
Pauli then proved that not all electrons could occupy the same, lower orbit through his exclusion principle and the modern view of atomic structure was born.