Chemical Reactions

4. the tiny pieces that all matter—all the stuff in the world—is made of
9. something that is made of all the same atoms or groups of atoms
10. a group of atoms joined together in a particular way
12. a process in which atoms rearrange to form new substances
13. the temperature at which a substance changes from the liquid phase to the gas phase
14. something that can be observed about a substance, such as color, smell, or boiling point
15. to change the order or position of something

1. letters and numbers showing the types and number of atoms that repeat to make up a substance
2. a substance that is added to soil to help plants grow
3. a starting substance that is part of a chemical reaction
5. the temperature at which a substance changes from the solid phase to the liquid phase
6. a structure formed by repeating groups of atoms that link together in a large network
7. able to cause damage
8. an ending substance that is made during a chemical reaction
9. the relative size of things
11. an object, diagram, or computer program that helps us understand something by making it simpler or easier to see