Correct Answer: Emission spectra

Solution : The correct option is Emission spectra.

Electrons in a metal absorb energy and migrate to higher energy levels when heated. When they return to lower energy levels, they produce light with specified wavelengths, resulting in an emission spectrum that is unique to each element. This method is employed in atomic emission spectroscopy for exact element identification, allowing scientists to analyse the composition of substances based on the colours of the emitted light.