When is the color emitted from an atom

Color is emitted from an atom when an electron jumps from a higher energy level to a lower energy level

Explanation:

According to Bohr's model of the atom, electrons are arranged into circular orbits, each orbit corresponding to a precise energy level.

In this model of the atom, electrons cannot be between two orbits: this means that the energy level of the atom are discrete, so they can only assume certain values.

As a result, when an electron jumps between two energy levels, it emits/absorbs a photon whose energy is equal to the difference in energy between the two levels.

In particular:

- If an electron jumps from a lower energy level to a higher energy level, it absorbs a photon

- If an electron jumps from a higher energy level to a lower energy level, it emits a photon

The energy of the emitted photon is equal to the difference in energy between the two levels, and it is related to the wavelength of the photon by

where h is the Planck's constant and c the speed of light.

For usual gases, the value of the energy E is such that the value of the wavelength falls within the visible light range of the electronmagnetic spectrums, so we observe light emitted as different colors, depending on the wavelength.