Excited Atoms in The Gas Phase

Explain why excited atoms in the gas phase emit or absorb only certain wavelengths of light

Electrons can only absorb or emit exact amounts of energy that allow them to make full jumps. This energy is known to be quantised, existing in light packets called photons.

According to Planck’s formula, absorbed or emitted energy is inversely proportional to wavelength. Therefore, electrons can only emit or absorb specific wavelengths.