The Bohr Model
Electrons in an atom are "quantized" - allowed to travel only in certain circular orbits and varying radii.
This simplified model of the atom is used in more elementary studies of Physics and Chemistry. Bohr himself understood that this was simplistic and argued that a space-time description of actual atoms and electrons is not possible.
This simplified model of the atom is used in more elementary studies of Physics and Chemistry. Bohr himself understood that this was simplistic and argued that a space-time description of actual atoms and electrons is not possible.
The Quantum Mechanical Model
Quantum mechanical model - electron location can only be spoken of in terms of a probability of being at a particular location. The electrons can be thought of as spread out in space as a "cloud" due to their wave nature. Many electron clouds are not spherical in shape. Electron clouds can also be interpreted as the probability of the position of the electron-its is impossible to tell exactly where it is at any time.
Quantum Mechanics reaffirms some aspects of Bohr's theory, such that electrons do only exist at certain defined states of energy, and that a photon of light is transmitted or absorbed when an electron makes a transition from one state to another.
Quantum Mechanics reaffirms some aspects of Bohr's theory, such that electrons do only exist at certain defined states of energy, and that a photon of light is transmitted or absorbed when an electron makes a transition from one state to another.