Burning a candle involves both physical and chemical changes. Here’s how each type of change occurs:
Physical Change:
- Melting of Wax: As the candle burns, the heat from the flame melts the solid wax into liquid wax. This is a physical change because it involves a change in state from solid to liquid without altering the chemical composition of the wax.
Chemical Change:
- Combustion of Wax: When the candle wick is lit, the heat causes the liquid wax to vaporize and mix with oxygen in the air, resulting in combustion. This is a chemical change because the hydrocarbons in the wax react with oxygen to produce carbon dioxide, water vapor, and heat. The original substances (wax and oxygen) are transformed into new substances (carbon dioxide and water), indicating a chemical reaction.
In summary, the melting of the wax is a physical change, while the actual burning (combustion) involves a chemical change. Both processes are integral to how a candle functions and contribute to its overall burning.