Question

How is an emission spectrum of an element generated?

Answer 1

The frequencies of light that an atom can emit are dependent on states the electrons can be in. When excited, an electron moves to a higher energy level or orbital. When the electron falls back to its ground level the light is emitted.

Answer 2

Answer is: When an electron in an atom returns from an excited state to a lower energy state.

Emission spectrum of a chemical element is the spectrum of frequencies emitted due to an atom making a transition from a high energy state to a lower energy state.

Emission spectrum has characteristic energy proportional to the frequency of the light.

Each element's emission spectrum is unique.