1. HOW DO ELECTRONS “SIT” AROUND THE NUCLEUS?

2. You are an usher at the Atomic Theatre. This theatre is a little unique. See the map of the theatre on the next slide.

3. Atomic Theatre Map Stage = seats Row 1 » Row 2 » Row 3 »

4. If 9 people showed up to the show, how would you seat them?

5. Is this what you might have done? Stage = seats Row 1 » Row 2 » Row 3 » = A person

6. Electrons orbit atoms in a similar matter.

7. Each row of the Atomic Theatre is like each energy level (orbital) of an atom. Stage or nucleus = approximate place where electron could be located. Remember electrons are constantly spinning around the nucleus.

8. Question #1 (answer in online lab notebook) How many electrons can the first energy level (orbital) hold?

9. Question #2 How many electrons can the 2 nd and 3 rd energy levels hold?

10. **SPECIAL PERIODIC TABLE REVIEW The atomic # on the periodic table equals the # of protons an atom contains. If there is no charge on the atom, the atomic # on the periodic table equals the # of electrons an atom contains. The atomic weight on the periodic table is the # of protons + the # of neutrons.

11. Question #3 Beryllium (Be) has an atomic # of 4 and an atomic weight of 9. How many electrons does Beryllium contain? Be 4 9

12. If you answered 4 electrons, you are correct. Before clicking the mouse, picture in your head how these 4 electrons are placed around the Beryllium atom’s nucleus

13. Is this what you came up with? Beryllium nucleus = electrons

14. On a scratch piece of paper draw how the electrons are placed around the element Sulfur (S). When you are finished, check your answer by clicking the mouse. S 16 24

15. Is this what you came up with? Sulfur nucleus = electrons

16. Question #4 How many electrons are in the first energy level of a Magnesium atom? Mg 12 24

17. Question #5 How many electrons are in the second energy level of a Magnesium atom? Mg 12 24

18. Question #6 How many electrons are in the third energy level of a Magnesium atom? Mg 12 24

19. FREE TIP-- An atom’s outer shell is the last energy level that contains electrons. Click to see an example.

20. There is 1 electron in Lithium’s (Li) outer shell. Lithium nucleus = electrons Li 3 7

21. Question #7 How many electron’s are in Hydrogen’s (H) outer shell? 1 1 H

22. Question #8 How many electrons are in Sodium’s (Na) outer shell? Na 11 23

23. Hey!! Are not Hydrogen, Lithium, and Sodium in the same column on the periodic table?

24. Why yes! H, Li, and Na are all in column 1A of the periodic table. H, Li, and N all have 1 electron.

25. Question #9 Gee, I wonder how many electrons are in the outer shell of the elements in column 5A? Column 5A includes wonderful elements like Nitrogen (N) and Phosphorus (P). N P 7 14 15 30

26. Question # 10 What is the correlation between the column # (based on where the column is located in the periodic table) and the # of electrons in the outer shell of the elements in that column?

27. Sooo, why do we care how many electrons are in the outer shell of an atom?

28. The # of electrons in the outer shell...... Determines many of an atom’s physical and chemical properties. (This is why elements in the same column behave similarly.) Determines how an atom will react with another atom and if those atoms will (drum roll please) form a CHEMICAL BOND.