Model, the electron orbits the nucleus in circular paths called energy levels or shells. These energy levels are denoted by the principal quantum number (n), with the lowest energy level being n=1.

The energy of each energy level is quantized, meaning that only certain discrete energy values are allowed. The energy of an electron in a particular energy level is given by the equation:

E = -13.6/n^2 eV

where E is the energy of the electron and n is the principal quantum number.

As the electron moves from a higher energy level to a lower energy level, it emits energy in the form of light or electromagnetic radiation. The emitted light has a frequency that can be calculated using the equation:

ΔE = hf

where ΔE is the change in energy, h is Planck's constant (6.626 x 10^-34 J·s), and f is the frequency of the emitted light.

The Bohr model also states that the electron can only occupy certain allowed orbits or energy levels. The electron can transition between these energy levels by either absorbing or emitting energy. When energy is absorbed, the electron moves to a higher energy level, and when energy is emitted, the electron moves to a lower energy level.

These energy level transitions are responsible for the characteristic emission and absorption spectra of elements. Each element has a unique set of energy levels, and when the electrons in these energy levels transition, they emit or absorb light at specific wavelengths, resulting in a distinct pattern of spectral lines. This pattern can be used to identify elements and study their atomic structure.