In the orbital model the negative electron planets rotate in circular orbits around the astral nucleus, similar to how the planets revolve around the sun, occupying the lowest possible energy orbit, or the orbit closest to the nucleus. In this model the electrons can only be in very fixed fixed orbits, denying all the others. Additionally, in each of these orbits, the electrons have a certain energy associated, which is greater in the more external orbits. This model was raised by Niels Bohr based on the hydrogen atom.
The electron clouds are regions of negative charge that surround an atomic nucleus that is associated with an atomic orbit. The region is defined mathematically as the one in which it is most likely to find electrons. The electron cloud model differs from the more simplistic model of Bohr, in which electrons orbit the nucleus much like planets orbit the Sun. In this model there are regions where an electron is likely to be found, called electron clouds, and they are used by chemists to map the atomic orbits of electrons.
