To determine chemical properties and experiment must be done in which some of the original substance is reacted with another substance. Chemical reactions have occurred when you change the physical and chemical properties of the original reactants. The new substance will have new properties that may be completely different. The properties of a substance are based on the underlying types and arrangement of atoms and molecules. The world of the unseen is our complete explanation for the observed properties.
Carbon comes in several forms.
Notice the differences between the two atomic structures.