Three distinct regions of candle flame

A candle flame is formedbecause wax vaporizes on burning. It has three distinct regions. The innermostzone, directly above the wick, contains wax that has been vaporized but that isunburnt. It is the darkest zone.

The middle zone isyellow and luminous. As it is an oxygen depleted zone, insufficient oxygenexists to burn all of the wax vapor. As such, partial combustion of wax takesplace. The zone also contains unburnt carbon vapor. The temperature in thisregion is hotter than the innermost zone, but cooler than the outer zone.

The outer zone is thearea where the flame is the hottest and complete combustion of wax takes place.It is light blue in color and not normally visible.