There are many examples of chemical energy present in the world. Some examples of chemical energy being used are combustion, batteries, photosynthesis, and respiration. Without this energy, plants and animals would not be able to survive. In addition, vehicular transportation would be largely, if not completely, impossible.

To understand how the examples of chemical energy work, it is necessary to understand chemical energy. Chemical energy is the energy that is stored in covalent bonds between atoms. When a reaction occurs, energy is either absorbed or released, since making a bond releases energy and breaking a bond requires energy. It is this release or absorption of energy that allows chemical energy to be so useful to organisms.

Plants use photosynthesis to create food. Photosynthesis takes the energy of the sun and uses it to turn carbon dioxide and water into sugar and oxygen. Chemical energy is stored in the bonds of the sugar molecule which can then be used by the plant or animals that eat the plant. The sugar is also used in another of the examples of chemical energy being used—cellular respiration.

Cellular respiration can be viewed as the opposite of photosynthesis. When a person eats organic molecules, a reaction takes place to break the sugar’s bonds. The result of this reaction is carbon dioxide, water, and energy that can be used to form adenosine triphosphate (ATP, an energy molecule. The body can then use ATP to do its work.

Another one of the examples of chemical energy being released is combustion—also known as burning. In many instances of combustion, light energy as well as heat energy is released. The result of this reaction is often carbon dioxide and water. Burning fossil fuels that power vehicles are examples of combustion. This is also the same reaction that occurs when logs are burning.

Batteries are also another of the examples of chemical energy being used. In this case, chemical energy is being transformed into electric energy. In a battery, there are two chemicals that are used, such as zinc and carbon. The chemical energy is transformed into electrical energy when a wire connects the two ends of a battery. In the case of a zinc carbon battery, the acid in the battery frees electrons in the zinc which can then move through the wire toward the carbon end. This allows the gadget connected to the battery to do its work.