Chemical reactions

1. letters and numbers showing the types and number of atoms that repeat to make up a substance
3. a structure formed by repeating groups of atoms that link together in a large network
7. able to cause damage
11. a starting substance that is part of a chemical reaction
12. the temperature at which a substance changes from the solid phase to the liquid phase
14. an ending substance that is made during a chemical reaction
15. something that can be observed about a substance, such as color, smell, or boiling point

2. a process in which atoms rearrange to form new substances
4. a substance that is added to soil to help plants grow
5. the relative size of things
6. a group of atoms joined together in a particular way
8. something that is made of all the same atoms or groups of atoms
9. the temperature at which a substance changes from the liquid phase to the gas phase
10. tiny pieces that all matter—all the stuff in the world—is made of
12. an object, diagram, or computer program that helps us understand something by making it simpler or easier to see
13. to change the order or position of something