1. Electron Arrangements Recall atomic number and the basic structure of a neutral atom – Oxygen – Atomic # = 8 – # of p + = 8 – # of n 0 = 8 – # of e - = 8 What are ‘valence electrons?’

2. Bohr Model Used for drawing because it is easiest to understand/draw/manipulate Remember, this is NOT how electrons move Why do we focus on valence electrons?

3. How do we know the # of Valence? Use – Electron configuration – Orbital diagrams – Periodic table

4. Aufbau Principle- electrons will first occupy orbitals of the lowest energy level

5. Pauli Exclusion Principle Pauli Exclusion Principle- maximum of TWO electrons in each orbital and they must have opposite spins – Electrons spin in one of two directions ↑ or ↓ Spin due to repulsion

7. Hund’s Rule Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin.

8. Read Chart on pg. 337 Read through and ask any questions you have pertaining to these rules Check through your homework from last night and ask questions now

9. Filling Orbitals Electron Configuration – 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 Orbital Diagram

10. Electron Configuration Write the electron configuration for an element in the third row (i.e. Na, Mg, Al, etc), an element in the fourth row (NOT K or Ca), and a noble gas. Write the orbital diagrams for the same three elements Why do you think the noble gases are so stable?

11. Tricks

13. Write the Electron Configuration Lithium Sodium Potassium – 1s 2 2s 1 – 1s 2 2s 2 2p 6 3s 1 – 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 Identify the following element: – 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 5s 1 Trends? Valence Electrons?? Trends? Valence Electrons??

15. Abbreviated/Noble Gas Configuration Instead of writing: – 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 1 for Gallium – Write this instead: [Ar] 4s 2 3d 10 4p 1 Instead of – 1s 2 2s 2 2p 6 3s 2 3p 4 for Sulfur – Write this instead: [Ne] 3s 2 3p 4 Your turn, instead of – 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 1

16. Exceptions to the Rule Half-filled and completely filled d and f subshells have extra stability. There are a few exceptions and they are all similar in nature but you must know these two: – Cr (shown below) – And Cu

17. Why do atoms bond with each other? Write out the orbital diagram for – One oxygen and two hydrogens – Sodium – Chlorine

18. Notes and Homework Take notes on the following in 11.11 (pg. 347) – Reactivity trend of metals and nonmetals on periodic table – Ionization energy Definition Trends – Atomic Size Definition Trends Pg. 354, #s 49-56 (a. and b. ONLY for all questions!) Electron config. for “S” and abbrev. config. for “C”

19. Write the orbital diagram Aluminum Neon Magnesium ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑ 1s2s2p 3s 3p ↑↓ ↑↓ ↑↓ ↑↓ ↑↓ 1s2s2p ↑↓ ↑↓ ↑↓ 1s2s2p 3s

20. Octet Rule/Duet Rule Main group elements (1a-8a) want to bond in a way that will give them 8 valence electrons H and He follow the duet rule

21. Draw Lewis Structure for: Li, B, N, F, and Ne Say you were trying to remove one electron from each of these and you wanted to quantify the amount of energy it took to remove that electron Match up the following values for energy with the correct element 520 kJ 2080kJ 800kJ 1681kJ 1402kJ

24. Reactivity Reactivity depends on how easily an element will gain or lose electrons There are two trends for reactivity Use this video to determine the first trend: https://www.youtube.com/watch?v=uixxJtJPV Xk https://www.youtube.com/watch?v=uixxJtJPV Xk

28. Shielding Electrons View the video about the Shielding Effect Explain this to your neighbor Take notes https://www.youtube.com/watch?v=XYKjQWl p0ZE&list=PLW0gavSzhMlSBD5uG0i9Dtj6nuQc 3pccK&index=4 https://www.youtube.com/watch?v=XYKjQWl p0ZE&list=PLW0gavSzhMlSBD5uG0i9Dtj6nuQc 3pccK&index=4

29. Types of Bonding Two types: – Ionic – Covalent Covalent can be further broken down into – Nonpolar covalent bonds – Polar covalent bonds Electrons are not shared equally If an element has a stronger ‘pull’ on electrons it obtains a partial negative charge δ- and the other element will have a partial positive charge δ+ This is called a dipole, ‘two poles’ one positive and one negative

30. Orbitals in Polar and Nonpolar What you think would happen..What actually happens..

31. Electronegativity Ability of an atom to attract shared electrons to themselves The polarity of a bond depends on the difference in electronegativity between the two atoms

32. Electronegativity Trends

33. Types of Bonds Generally: Difference of 1.7 or greater = Ionic Bond Difference below 1.7 = Polar Covalent Difference below 0.5 = Nonpolar Covalent BondElectronegativity ValuesBond type Cl-Cl(3.0) H-F(2.1) (4.0) H-S(2.1) (2.5)

34. Water What type of bond occurs between O-H in a water molecule? Draw a water molecule, indicating the partial charges on the correct atoms Hydrogen bonding occurs in water molecules

35. Practice drawing molecules Draw Lewis structure for – Fluorine gas (pure) – HBr – PH 3 – CO 2 – CN -

36. Rest of Class Complete Ionic/covalent Bond Practice WS Work on homework problems

37. Common tent materials are somewhat rainproof in that the surface tension of water will bridge the pores in the finely woven material. But if you touch the tent material with your finger, you break the surface tension and the rain will drip through. help the cleaning of clothes by lowering the surface tension of the water so that it more readily soaks into pores and soiled areas.

38. Adhesion and Cohesion Adhesion- water being attracted to other substances Cohesion- water being attracted to other water molecules (itself)

39. Hydrogen Bonding in Water Make a paperclip (many times more dense than water) float on water! – Place a small square of paper in water so it floats – Carefully (maybe use tweezers?) place paperclip on top of paper so it floats – Tap lightly on paper with pencil so the paper begins to sink but the paperclip doesn’t! – Get at eye level and look closely at paperclip and water

40. Homework Pg. 356 #s 79-82 Pg. 393 #s 12-28 evens Print “Ionic and Covalent Bonding Activity” *only pgs 5-10*