Which quantum numbers describe the energy level of an electron?

The principal quantum number, denoted as 'n', is the key quantum number that describes the energy level of an electron in an atom. This number indicates the main energy level, or shell, in which the electron resides. The values of 'n' can be whole numbers starting from 1 (n=1, 2, 3, etc.), and as 'n' increases, the energy level of the electron also increases, along with the average distance of the electron from the nucleus.

The higher the principal quantum number, the greater the energy and the larger the orbitals. Therefore, 'n' directly correlates with the energy levels in an atom, making it crucial for understanding electron configurations and the overall chemical behavior of elements. Other quantum numbers, such as spin, angular, and magnetic, describe different properties of electrons but do not provide direct information about the energy level.