3. Monday, Nov. 4 th : “A” Day Tuesday, Nov. 5 th : “B” Day Agenda  Electron Configuration Review  Finish Electron Configuration Video and WS/collect  Electron Configuration “shorthand” notation  In-class: Section 3.3 review: pg. 99: #1-8, 11 due today  Homework: “Introduction to the Elements” worksheet Concept Review: “Electron Configuration”

4. Electron Configuration Practice  Use arrows AND electron configuration notation to write the electron configuration for an atom that has 17 electrons. Use the orbital filling chart to place the 17 electrons in their proper orbitals: ____ ____ ____ ____ ____ ____ ____ ____ ____ 1s 2s 2p 2p 2p 3s 3p 3p 3p 1s 2 2s 2 2p 6 3s 2 3p 5

5. Electron Configurations Using Shorthand Notation  As you move from left to right across the periodic table, each element’s electron configuration builds on the previous configuration.  To save space, electron configurations can be written based on the configurations of the noble gases (neon, argon, krypton, and xenon).  The noble gases are located in the last column on the right-hand side of the periodic table.

6. Electron Configurations Using Shorthand Notation  Sulfur (atomic number 16) has 16 electrons.  The electron configuration for sulfur (S) is: 1s 2 2s 2 2p 6 3s 2 3p 4  Neon is the noble gas that appears before sulfur in the periodic table.  Neon’s configuration is 1s 2 2s 2 2p 6  We can substitute [Ne] for the 1s 2 2s 2 2p 6 part of sulfur’s electron configuration and just write: [Ne] 3s 2 3p 4

7. Practice  Write the electron configuration for potassium using shorthand notation. Potassium has 19 electrons (atomic # = 19)  The electron configuration for potassium (K) is: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 Argon is the noble gas that appears before potassium in the periodic table. Argon’s configuration is 1s 2 2s 2 2p 6 3s 2 3p 6  We can substitute [Ar] for the 1s 2 2s 2 2p 6 3s 2 3p 6 part of potassium’s electron configuration and just write: [Ar] 4s 1

8. Additional Practice  Write the electron configuration for boron using shorthand notation. Boron has 5 electrons (atomic # = 5)  The electron configuration for boron (B) is: 1s 2 2s 2 2p 1 Helium is the noble gas that appears before boron in the periodic table. Helium’s configuration is 1s 2  We can substitute [He] for the 1s 2 part of boron’s electron configuration and just write: [He] 2s 2 2p 1

9. In-Class Assignment/Homework  Finish “Writing Electron Configurations” worksheet – due today.  Sec. 3.3 review, pg. 99: #1-8, 11 #5 and #6: use BOTH arrows/circles AND electron configuration notation.  When you finish, turn it in and pick up the homework worksheet…

10. “Introduction to the Elements” Video Follow-Up Questions  This worksheet is a really good review of the material that we’ve covered so far in chapter.  Show me how smart you are by completing the worksheet without even watching the video!

11. Looking Ahead  We will finish chapter 3 next time by covering section 3.4: “Counting Atoms”. Chapter 3 Test Concept Review/KWL due: Monday, Nov. 18 th : “A” Day Tuesday, Nov. 19 th : “B” Day