1. CHEMISTRY - the study of matter and its changes

2. ATOM - fundamental part of matter

3. PROTON - positively charged particle

4. ELECTRON - negatively charged particle

5. LAW - a compilation of observations describing processes in the universe

6. HYPOTHESIS - an educated guess

7. VOLUME - the 3D space an object takes up

8. MASS - a measure of the amount of matter in an object

9. ELECTRON - a negatively charged particle

10. ALPHA PARTICLE - a helium nucleus

11. GRAM - SI unit of mass

12. METER - SI unit of length

13. LITER - SI unit of volume

14. SECOND - SI unit of time

15. MOLE - formula mass of the compound is one mole

16. COEFFICIENT - the number in front of a variable

17. HUND’S RULE electrons in one orbital must have opposite spins.

18. ORBITAL a topology representing the probability of finding an electron in a region around the nucleus of an atom.

19. ENERGY ability to do work

20. ANEMOMETER device that measures the speed of the wind