Question

Different gases in the discharge tube produce different colors under suitable conditions of pressure and voltage. Explain.

Answer 1

1. A discharge tube is an arrangement of electrodes in a gas within an insulating, temperature-resistant envelope.
2. A discharge tube is an electrical device in which current flow is by electrons and ions in an ionized gas, as in fluorescent light or a neon tube.
3. The electrons in gases are excited to higher energy states by energy.
4. Electrons emit extra energy in the form of light in order to return to the ground state.
5. Because distinct wavelengths of light must be discharged in each instance, the light in each tube is coloured differently.
6. The colors of the tubes vary because various elements emit different wavelengths of light to return to their respective ground states.