The person who discovered physical and chemical change was Josiah Willard Gibbs. He was born on 11, 1839, and contributed immensely to science, especially the theoretical aspect of mathematics, chemistry, and physics. He discovered physical and chemical change during a series of experiments he performed between 1876 and 1878.
Due to his immense contributions to science, he was one of the American scientists to have earned an international reputation. Chemical change refers to the process of changing reactants into products, either by making or breaking chemical bonds.
Physical change, on the other hand, refers to a change that only affects the form of a substance, but not its chemical compositions. An example of a physical change is the one that occurs in mixtures. When you have a mixture, it won't result in a change in its chemical compositions. Another thing is that you can still separate the components of a mixture.