A fluorescent tube is a glass tube with a fluorescent coating on its inner surface containing mercury vapour at low pressure.
The free electrons are accelerated when a p.d. is applied to the tube.Electrons flow through the tube and collide with orbiting atomic electrons within the mercury atoms transferring their energy to them.This results in the electrons being raised to a higher level within the mercury atoms.The coating on the inside surface of the glass absorbs the u.v. photons emitted by the mercury atoms.The coating emits photons in the visible spectrum as the atoms de-excite.Fluorescent tubes waste only a few watts of power.A fluorescent tube emits visible light.Ionisation and excitation of mercury atoms occurs as they collide with each other and electrons.Mercury atoms emit u.v. photons and visible photons when they de-excite.U.V. photons are absorbed by atoms of the fluorescent coating.These atoms excite then they de-excite in steps emitting visible photons.
The free electrons are accelerated when a p.d. is applied to the tube.Electrons flow through the tube and collide with orbiting atomic electrons within the mercury atoms transferring their energy to them.This results in the electrons being raised to a higher level within the mercury atoms.The coating on the inside surface of the glass absorbs the u.v. photons emitted by the mercury atoms.The coating emits photons in the visible spectrum as the atoms de-excite.Fluorescent tubes waste only a few watts of power.A fluorescent tube emits visible light.Ionisation and excitation of mercury atoms occurs as they collide with each other and electrons.Mercury atoms emit u.v. photons and visible photons when they de-excite.U.V. photons are absorbed by atoms of the fluorescent coating.These atoms excite then they de-excite in steps emitting visible photons.