1. Phisical change: a change in size , shape , or state , without forming a new substance.
2. Chemical change: a change in matter that produces a new substance with different properties from the original.
3.Chemical reaction: a chemical change of original substances into one or more new substances.
4.Reactant: one of the original substances before a chemical reaction takes place.
5. Product: one of the new substances produced when a chemical reaction takes place.