Chemistry

2. the smallest unit of a substance that has all the properties of that substance
5. anything that has weight and takes up space
6. extremely small and are made up of a few even smaller particles
9. the smallest possible unit of a chemical element
10. something that has a length width and thickness
11. substances that can move around freely
13. A substance able to increase the rate of a chemical reaction without itself being consumed or changed by the reacting chemicals
15. a particle that has a mass nearly equal to that of the proton but no electrical charge

1. quantity of matter in a physical body
3. a science that deals with the composition and properties of substances and of the changes they undergo
4. a very small particle that exists in the nucleus of every atom
7. knowledge about the world that is based on facts learned through experiments and observation
8. a very small particle that has a negative charge of electricity
12. material, or matter, of which something is made
14. matter that moves easily