Flourescent Lamps

Light is a form of energy that can be released by an atom. It is made up of many small particle-like packets that have energy and momentum but no mass. These particles, called light photons, are the most basic units of light. Atoms release light photons when their electrons become excited. An atom's electrons have different levels of energy. Electrons of different energy levels occupy different orbitals. Generally, electrons with greater energy move in orbitals farther away from the nucleus.

When an atom gains or loses energy, it causes the electrons to move. For example, when heat passes energy on to an atom, an electron may be temporarily boosted to a higher orbital. The electron only stays in this position for a

When you turn the lamp on, the current flows through the electrical circuit to the electrodes. The voltage across the electrodes will make the electrons migrate through the gas from one end of the tube to the other. This energy changes some of the mercury in the tube from a liquid to a gas. As electrons and charged atoms move through the tube, some of them will collide with the gaseous mercury atoms. These collisions excite the atoms, bumping electrons up to higher energy levels. When the electrons return to their original energy level, they release light photons.

tiny fraction of a second; then it is immediately drawn back toward the nucleus, to its original orbital. As it returns to its original orbital, the electron releases the extra energy in the form of a photon, in this case a light photon.

The most important element in a fluorescent lamp is the sealed glass tube. The tube contains a small bit of mercury and a gas, argon, kept under very low pressure. The tube is also coated along the inside of the glass with phosphor powder. The tube has two electrodes, one at each end, which are wired to an electrical circuit. The electrical circuit, is hooked up to an alternating current (AC) supply.

This surge in current helps build the initial voltage needed to establish the electrical arc through the gas, and the electrical current now flows through the tube. The free electrons collide with the atoms, knocking loose other electrons, which creates ions. The result is a plasma, a gas made of free moving ions and electrons. This creates a path for an electrical current. The flying electrons keeps the two filaments warm, so they continue to emit new electrons into the plasma. As long as there is AC current, and the filaments aren't worn out, current will continue to flow through the tube. The problem with this sort of lamp is it takes a few seconds for it to light up. These days, most fluorescent lamps are designed to light up almost instantly.

When the current

Some topics in this essay:
, fluorescent lamps, electrical current, light photons, fluorescent lamp, light bulbs, incandescent light, free electrons, mercury atoms, visible light, incandescent light bulbs, release light photons, current flows, ions free electrons, fluorescent lamps complex, electrons energy levels,