Final answer:
The Bohr model suggests that electrons can only exist in specified energy states called orbits or shells. Each shell has a specific energy level, and the electrons must occupy one of these energy states. Moving from one energy level to another requires the absorption or emission of specific amounts of energy.
Step-by-step explanation:
The model that suggests that electrons can only exist in specified energy states is known as the Bohr model of the atom. According to this model, the electrons encircle the nucleus of the atom in specific allowable paths called orbits or shells. Each shell has a specific energy level, and the electrons must occupy one of these energy states.
The energy levels in the Bohr model are quantized, meaning that they can only have certain fixed values. Moving from one energy level to another requires the absorption or emission of specific amounts of energy.
For example, in the hydrogen atom, the ground state is when the electron is in the orbit closest to the nucleus, with the lowest energy. When the electron absorbs energy, it can jump to a higher energy level, but it quickly returns to the ground state, releasing a photon of light.