Flame: Encyclopedia - Flame

Flame

A flame is a self-sustaining oxidizing chemical reaction most often producing carbon dioxide and gaseous water. It consists of reacting gases emitting heat and light, which is dependent on the chemical composition of the burning flame. In many cases such as burning organic matter like wood or incomplete combustion of gas, incandescent solid particles (soot) produce the familiar red-orange 'fire' color light. This light has a continuous spectrum. Complete combustion of gas has a dim blue color due to the emission of single wavelength radiations from various electron transitions in the excited molecules formed in the flame. Usually oxygen is involved, but hydrogen burning in chlorine produces a flame as well, producing hydrogen chloride HCl. Other possible combinations producing flames (amongst many more) are fluorine and hydrogen or hydrazine and nitrogen tetroxide.

Flame - Flame Colors

Image:Flames.jpg

The image at right demonstrates the difference in flame colors depending on how complete the combustion is. Pictured is a bunsen burner burning mainly methane. When the gas is burnt it burns with yellow flame, also called a safety flame, at 1,000 C. When the flame is blue, using the heat color rule it is much hotter, around 1,600 C. Flame temperatures of common items include a blowlamp at 1,300 C, a candle at 1,400 C, or a much hotter oxy-acetylene combustion at 3,000 C.

Generally speaking, if the flame is red, that is the cooler part of the flame, then it goes to orange, yellow, white, violet and blue and bright blue, as the temperature increases. For a given flame's region, the closer to white, blue, or bright blue on this scale, the hotter that section of the flame is.

Flame - See Also

• Fire
• Combustion

Categories: Articles to be merged | Cleanup from November 2005

Adapted from the Wikipedia article "Flame", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki