The primary forms of energy produced by a burning candle are heat and light. These come from the burning of fuel, in this case wax and, to a much lesser extent, the string of the candle's wick.
Chemical bonds are the basis of the energy released in the form of heat and light when a candle burns. Their dissolution during the process of the candle's burning, precipitated by rising temperatures and resulting increases in the agitation of molecular structures, produce these visible and tangible forms of energy. Many other forms of energy are also at work during this process, though to much lesser degrees.
Other forms of energy related to candles include:
- Sound, given off in small quantities during burning.
- Kinetic energy is released when the wax melts and rolls.
- Surface energy is produced when air and molten wax interact.
In addition to these forms of energy produced, the wax itself oxidizes during the burning process. The potential energy contained in the chemical bonds within the wax releases water and carbon dioxide. Paraffin is pure enough that the hydrocarbon atoms produced during this process can burn away entirely, which lends fuel to the reaction so long as the wax is kept close to the flame by a holder or jar and not allowed to roll down the length of the candle.