Chemical Reactions

In a chemical reaction, bonds between molecules of the reactant are broken and new bonds between molecules of the product are established to create a new substance. Chemical reactions occur all around us, including in our body's digestion of food and the creation of the sunlight's light. Understanding physical and chemical changes is crucial before starting any chemical processes. The finest illustration of a physical and chemical change is a burning candle. Light a candle if you have one. We can see that the candle turns into wax as time goes on. The candle will go out if a container is placed over it. In the example, burning the candle is a chemical change, but converting the candle to wax is a physical change. A physical change results in a change in the state of the material, whereas a chemical change results in the formation of a new substance in which either energy is given off or absorbed. Thus, we might assume that chemical changes are accompanied by physical modifications.