HOW A NEON TUBE WORKS
A neon light is a sealed tube filled with low-pressure neon gas. At one end of the tube there is an electrical supply coming from the negative ‘cathode’ (-), and at the other end there is a positive ‘anode’ (+). The electrical supply sends electrons from the cathode (-) to the anode (+), while the neon atoms move randomly in the tube. All these interactions lead to the expulsion of coloured photons from the neon ions and atoms, creating the distinctive red- orange glow of the neon light. Different ‘neon light’ colours are not actually caused by neon but come from other noble gases. Helium glows pink-yellow, argon lavender blue, krypton green and xenon light blue- green.