The Nucleus

2. Atomic number 3.
4. Atomic number 13.
6. Latin word for silver and the reason why it's element symbol is Ag.
7. 53 protons
8. Thousands of times smaller than the atom as a whole, these are held together by a fundamental force: the nuclear force and are very stable. They rarely change.
9. The total number of protons and neutrons in a nucleus.
14. Same size as a proton but neutral.
15. The word "atom" comes from this Greek word.
18. A well tested set of ideas that explain many observations.
19. Small, almost massless, and negatively charged.
20. Heavy and positively charged.

1. The number of protons always determines the ______________.
3. Neutrons act as a __________ between protons so that they don't repel.
5. Protons and Neutrons, because they hang out in the nucleus.
6. The number of protons in an atom.
10. Stuff is made of _________.
11. He proved the existence of atoms in 1905.
12. Chemistry is the study of how three tiny particles form _____________.
13. 16 protons
16. The random motion of pollen grains due to collisions with the atoms and molecules surrounding them.
17. 47 protons