When a candle burns, chemical changes occur. What are these changes?
The burning of a candle is a form of combustion. For combustion to occur, three things are needed: fuel, oxygen, and a spark to initiate it. The oxygen is from the atmosphere, the spark is the match used to light the candle, and the candle wax is the fuel for the flame. The actual string that burns buried in the wax is called the wick and while it does slowly burn, the surrounding wax is what truly fuels the flame. The wax is a hydrocarbon, meaning it is a chemical made of carbon and hydrogen. The heat from the flame melts nearby wax which is then drawn up through the wick to the flame to burn. The hydrocarbons burn in the presence of oxygen to produce carbon dioxide, water vapor, and energy in the form of the flame.