Why are atomic spectra not continuous?

Explanation

Each electron in an atom is associated with a definite eneryg corresponding to different energy levels. These electrons absorb energy from various external sources (like heat, light, etc.) and are promoted to higher energy levels. These excited electrons radiate different amount of energy and return to ground state. since the difference between any two energy levels is fixed, the atomic spectra obtained are discontinuous line spectra having fixed wavelengths. the spectrum so obtained consists of a few bright lines,, but does not contian all the possible specttra having fixed wavelengths. the spectrum so obtained consists of a few bright lines, but does not contain all the possible spectral lines corresponding to a range of given wavelengths. thus, atomic spectra are not continuous.