jan 1, 1913 - Niels Bohr

Description:

Danish physicist.
He studied the structure of an atom.
He set about trying to solve the problems with Rutherford’s model.
He realised that classical physics could not properly explain what was going on at the atomic level; instead, he invoked quantum theory to try and explain the arrangement of electrons.
He suggested that electrons didn't spiral into the nucleus, but orbit in different levels.
Electrons could move between these energy levels (referred to by Bohr as ‘stationary states’), but had to do so by either absorbing or emitting energy.

This is called the Bohr model, or the quantum model.
This model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons.