2. Atoms

3. Is made Up of 2 Parts: The Nucleus: 1. Protons 2. Neutrons The Rings: 1. Electrons

4. How to Make an Atom: Protons = Atomic # 1.Protons: Look at the atomic # and draw the number of Protons. 2.Electrons: Same as Protons. Want to keep + / - balance.

5. How Do you Find # of Neutrons? : 2. Neutrons: Round the atomic Mass to the nearest whole number (7) 3. then subtract the atomic # from the atomic Mass. (7- 3=4) 3 Li 6.94

6. How to Make an Atom: 4.Electrons: Is the same number as the Protons, and Atomic #. 5.Place them on the Rings. But Remember: 1st Ring = 2 E 2nd Ring = 8 E 3rd Ring = 18 E

7. Practice: 3 Li 6.94 5 B 10.81

8. More Practice: 10 Ne 20.18 20 Ca 40.08

10. 1. What is the Atomic # of Calcium: A.40.08 B.20 C.19 D.80 20 Ca 40.08 B

11. 2. How many protons does a Cobalt atom have? A. 30 B. 27 C. 58.93 D. 26 27 Co 58.93 B

12. 3. What is the Atomic Mass of Hydrogen? A. 1 B. H C.1.01 D.100 1 H 1.01 C

13. 4. How many electrons does Potassium have? A. 19 B. 39.10 C. 40 D. 39 19 K 39.10 A

14. 5. How many neutrons does Beryllium have: A. 4 B. 6 C. 9.01 D. 5 4 Be 9.01 D

15. 6. How many neutrons does Boron have? A. 5 B. 10.00 C. 6 D. 10.81 5 B 10.81 C

16. 7. How many shells does an atom of Nitrogen need? A. 1 B. 2 C. 3 D. 4 7 N 14.01 B

17. 8. How many shells does Carbon have? A. 6 B. 2 C. 3 D. 4 6 C 12.01 B

18. 9. How many electrons does Magnesium have? A. 12 B. 24.31 C. 13 D. 14.31 12 Mg 24.31 A

19. 10. How many shells does Hydrogen have? A. 1 B. 2 C. 3 D. 4 1 H 1.01 A

20. 11. How many protons does Silicon have? A. 16 B. 28.09 C. 15 D. 14 14 Si 28.09 D

21. 12. What is the atomic mass of Aluminum? A. 13 B. 27 C. 26.98 D. 5 13 Al 26.98 C