* Combination: The wax (hydrocarbon) in the candle combines with oxygen from the air. This is an exothermic reaction, meaning it releases heat and light.

* Decomposition: The heat from the combination reaction causes the wax and oxygen to break down into simpler products, primarily carbon dioxide and water vapor.

Let's break it down further:

1. Combustion: The candle wax (a hydrocarbon) reacts with oxygen (O2) from the air. This is a combination reaction, as two substances combine to form a new substance.

* Equation: Hydrocarbon + Oxygen → Carbon dioxide + Water + Heat and Light

2. Decomposition: The heat generated from the combustion reaction breaks down the wax and oxygen molecules into simpler molecules. This is a decomposition reaction, as a single substance breaks down into two or more substances.

Therefore, burning a candle involves both combination and decomposition reactions.

It's important to note that the reaction is a complex process with several intermediate steps, and the overall equation represents the simplified net reaction.