Physical vs. Chemical Changes

In a physical change, the particles are rearranged so only the appearance of the substance changes. The atoms and molecules themselves do not change and so the properties of the substance do not change. In a chemical change, a new chemical is made. This means that the atoms have been moved around into new arrangements. In some chemical changes, molecules can be separated to make new chemicals. Sometimes atoms and molecules join together to make new chemical substances with larger molecules. New substances have new particles and new properties. Both the physical and chemical properties of the new substance (the product) will be different from that of the original substance (the reactant).