Chemical Reactions

3. Letters and numbers showing the types and number of atoms that repeat to make up a substance.
4. The temperature at which a substance changes from the solid phase to the liquid phase.
6. Something that can be observed about a substance, such as color, smell, or boiling point.
7. The tiny pieces that all matter—all the stuff in the world—is made of.
9. An ending substance that is made during a chemical reaction.
13. Able to cause damage.
14. An object, diagram, or computer program that helps us understand something by making it simpler or easier to see.
15. A process in which atoms rearrange to form new substances.
16. The relative size of things.

1. A starting substance that is part of a chemical reaction.
2. To change the order or position of something.
5. A structure formed by repeating groups of atoms that link together in a large network.
8. Something that is made of all the same atoms or groups of atoms.
10. A group of atoms joined together in a particular way.
11. A substance that is added to soil to help plants grow.
12. The temperature at which a substance changes from the liquid phase to the gas phase.