It is not only the earth which is governed by the law of matter and energy but the entire universe work on this concept. As per the law of matter and energy, both the matter and energy remains constant. The matter is composed of atoms and as per the conservation laws it is neither created nor destroyed, thus the number of atoms in a matter remains constant before and after conversion from one form to another. While energy can also be neither created nor destroyed but its form can be changed from one to another.
