Neil Bohr is the one that came up with this theory.
* Electrons revolve around the nucleus in fixed circular path call orbits
* the electron can travel indefinitely within an energy level without loosing energy
* every orbit has a definite energy
* the orbit shells further away from the nucleus have high energy
* Electrons in lower orbit can absorb energy and move to a higher orbit, these electrons are known as excited electrons
* these excited state electrons can come to the ground state by emitting the additional energy it possesses.
1. The atom is neutral.
2. The protons in a nucleus should only repel each other
3.The electrons in the nucleus would push apart the protons.
4.We can see clear evidence of another force in the world around us.