1. The smallest particle that still behaves like the original matter it came from. Atom

2. Two or more atoms joined together. Molecule

3. Matter made up of only one kind of atom. Element

4. A physical change that occurs when matter changes from one state to another, such as from a liquid to a gas. Change of State

5. A change in which the form of a substance changes but the substance still has the same chemical makeup. Physical Change

6. Two or more substances that are combined without being changed. A mixture.

7. A property that involves a substance by itself. Physical Property

8. A property that involves how a substance interacts with other substances. Chemical Property

9. A reaction or change in a substance, produced by chemical means, that results in a different substance. Chemical Change

10. A chemical change. Chemical reaction

11. A substance made of two or more different elements. Compound

12. The total mass of the products that form in a chemical reaction is equal to the total mass of the substances that react. Law of conservation of mass