Plants store energy in the form of polysaccharides. Dry wood is largely composed of cellulose, which is a type of polysaccharide. When wood burns, the stored energy in the polysaccharide molecules within the plant tissue is released as light and heat. The total amount of energy released as light and heat equals the amount of energy that was originally stored in the polysaccharide molecules. This process is an example of the .

This process is an example of the first law of thermodynamics.

Explanation:

The first law of thermodynamics states that energy can neither be created nor destroyed but it can be transformed from one form to the other.

It is also known as the law of conservation of energy. In the first law of thermodynamics, heat can be described as a form of energy.

In the first law of thermodynamics, the total amount of energy originally present in the system is equal to the total amount of energy released by the system.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds