Bohr’s model of the atom, built upon Rutherford’s nuclear model, introduced the concept of quantized energy levels and orbits for electrons. Here’s a breakdown of the main postulates:
1. Electrons Orbit the Nucleus in Specific, Circular Paths (Orbits):
Electrons don’t move in any random path around the nucleus; instead, they are confined to specific, circular orbits, which are also called energy levels or shells.
2. Energy Levels are Quantized:
Each orbit (energy level) has a specific, fixed amount of energy.
3. Electrons Do Not Radiate Energy While in Stationary Orbits:
As long as an electron remains in a specific orbit, it doesn’t emit or absorb electromagnetic radiation, according to this principle.
4. Energy Transitions Involve Radiation Absorption or Emission:
Electrons can move from one orbit to another by absorbing or emitting energy in the form of photons.
When an electron moves from a higher energy level to a lower one, it releases a photon with energy equal to the difference in energy between the two levels, resulting in the emission of light.
Conversely, when an electron absorbs a photon of the correct energy, it can move from a lower to a higher energy level.