Energy is stored in chemical compounds. This energy is called chemical energy. Chemical energy is a form of potential energy. When bonds between atoms are broken, energy is released. The wood in fireplaces has chemical energy. The energy is released as heat and light when the wood burns. Most living things get their energy from food. When food molecules are broken down, the energy is released. It may then be used to do work, like playing ball or studying science. If you have ever heard, "Eat a good breakfast", thats why. You need energy to do things during the day. To do those things you need energy. You get your energy from the food you eat. That energy is stored in your body until you need it. How did you get to school today? If you walked, you used chemical energy from the food you ate. What if you rode the bus or were driven in a car? Where did that energy come from? 
In order for you to walk, what happens to bonds between atoms?
They are fused together