Let's start this week's wonder off with a riddle: What burns longer, a red candle or a green candle?
Answer: Neither, they both burn shorter!
Candles are made out of wax. Wax, specifically paraffin wax, is composed of hydrocarbons. That means that it's made of hydrogen and carbon atoms. As a candle burns, it undergoes a chemical reaction.
When you light a candle, heat causes the wax to melt. It changes from a solid to a liquid. As the candle continues to burn, it is drawn up the wick towards the flame. The melted wax then begins to evaporate as it turns into a gas. Its molecules are oxidized, releasing water and carbon dioxide into the surrounding atmosphere. This reaction also produces light and heat. The process continues until the candle "disappears!"