Do Now

1. Below are several Lewis dot diagrams, all having errors. Find the errors, explain why they are errors, and correct them. • • • • Al • N • • He • • • • • • • • • • Do Now

2. Lewis Dot Diagrams

3. Write element symbol • Determine # of valence electrons • Equal to group # • Draw dots around symbol • # of dots = # of valence electrons • Put 1 dot per side before you pair dots up Reviewing Lewis Diagrams

4. B 4 8 7 1 5 3 6 2 Lewis Symbols

5. Cl Lewis Symbols

6. In compounds, atoms tend to achieve noble gas electron configurations • Metals lose to achieve octet in lower energy level • Non-metals gain to get 8 if combine with metal • or can share with other non-metals • Metal cation + non-metal anion = ionic bond (chapter 7) • 2 non-metals = covalent bond (chapter 8) • 2 metals = metallic bond (also chapter 7) Octet Rule Review

7. Covalent Bonding

8. Between non-metals • Electrons are shared between atoms • Neutral • Makes molecules Covalent Bonds

9. Chemical formula = molecular formula • Not lowest whole number, just actual number of atoms of each element • Properties • Comprised of two or more non-metals • Not good conductors of heat and electric current • Lower melting and boiling points than ionic • Diatomic molecules • Molecule of 2 identical atoms • H2 O2 N2 Cl2 Br2 I2 F2 Molecular compounds

10. Draw the Lewis dot diagrams for all the atoms in CH4 • Draw 1 carbon diagram • Draw 4 hydrogen diagrams How Covalent Bonds Form

11. C H H H H Bonding in Methane

12. C H H H H Bonding in Methane

13. H C H H H Bonding in Methane

14. H C H H H Bonding in Methane

15. H C H H H Bonding in Methane

16. H H C H H Bonding in Methane

17. H H C H H Bonding in Methane

18. H H C H H Bonding in Methane

19. H H H C H Bonding in Methane

20. H H H C H Bonding in Methane

21. H H H H C Bonding in Methane

22. H C H H H Bonding in Methane

23. PCl3 H2O SF2 AlCl3 Draw the following compounds:

24. Get out your homework to be stamped and be prepared to answer: • What is a covalent bond? • What types of elements do covalent bonds form between? • What are valence electrons? • How many electrons are in a bond? Do Now:

25. Two electrons are shared between two atoms • 1 electron pair • Represented by 1 line between the atoms Single Bond

26. Let’s Make F2 F F

27. Let’s Make F2 F F

28. Let’s Make F2 F F

29. Four electrons are shared between two atoms • 2 electron pairs • Represented by 2 lines between the atoms Double Bond

30. O O Let’s Make O2

31. O O Let’s Make O2

32. O O Let’s Make O2

33. O O Let’s Make O2

34. Draw the Lewis dot diagram for • O3 • CO2 • CF2S Double bonds Try It!

35. Six electrons are shared between two atoms • 3 electron pairs • Represented by 3 lines between the atoms Triple Bond

36. N N Let’s Make N2

37. N N Let’s Make N2

38. N N Let’s Make N2

39. Let’s Make N2 N N Let’s Make N2

40. N N Let’s Make N2

41. Draw the Lewis Dot Diagram for • HCN • N2O • C2H2 Triple bonds Try It!

42. Place shared electrons between the 2 symbols either as pair of dots or dashes • Ex H-H or :Ö=Ö: or :N≡N: • Each dash represents a single covalent bond • Unshared pairs / lone pairs / non-bonding pairs = valence e- pairs not in covalent bond • Structural formulas use dashes, but also show spatial arrangement of atoms • Oriented to maximize distance between e- pairs (bonded or unshared) Lewis Structures summary

43. Covalently bonded • With additional or removed electrons • Cations lose and anions gain in e- count NO31- SO32- PO43- CN1- Polyatomic Ions

44. Making Sense

45. Making Sense

46. Making Sense

47. Ionic Compounds

48. Atom that has gained or lost electrons • Cation (+) • Anion (-) Ion Na Cl

49. Transfer of electrons between atoms • Opposite charges formed • Creates attraction between the ions • Called electrostatic force Ionic Bonds

50. Cl Na