Sylvania Blacklight Blue Fluorescent Light Bulbs
A fluorescent light bulb
uses a completely different method to produce light. There are electrodes at both ends of a fluorescent tube, and a gas containing argon and mercury vapor is inside the tube. A stream of electrons flows through the gas from one electrode to the other (in a manner similar to the stream of electrons in a cathode ray tube). These electrons bump into the mercury atoms and excite them. As the mercury atoms move from the excited state back to the unexcited state, they give off ultraviolet photons. These photons hit the phosphor coating the inside of the fluorescent tube, and this phosphor creates visible light. It sounds complicated, so lets go through it again in slow motion
There is a stream of electrons flowing between the electrodes at both ends of the fluorescent bulb.
The electrons interact with mercury vapor atoms floating inside the bulb.
The mercury atoms become excited, and when they return to an unexcited state they release photons of light in the ultraviolet region of the spectrum.
These ultraviolet photons collide with the phosphor coating the inside of the bulb, and the phosphor creates visible light.