1. Reminder When the timer reaches 0:
You must have your notebook out and open,
Have a pen or pencil ready
And, if there was homework, have it out on your desk.
Then, copy the objective and ANSWER the Do Now questions.

2. Objective: SWBAT differentiate between ionic and covalent bonding.
4 January 2010
Objective: SWBAT differentiate between ionic and covalent bonding.
Do Now:
Write the name for Pb(NO3)2
Is Pb(NO3)2 ionic or covalent?
Name one PROPERTY of ionic compounds.

3. Announcements
Four days this week – Covalent compounds – properties, names, drawing diagrams.
Two days next week – shapes of covalent molecules.
Then, midterm review (4 days)!!
Midterms are the (short) week of January 18.

4. Announcements
I will post missing assignments for quarter 2 tomorrow in room 104.
If you haven’t taken the Ions and Ionic Compounds test, you must do so by Friday!!!
Seating survey tomorrow; new seats later this week.

5. What do you remember about ionic bonding and ionic compounds?
Which elements? Electronegativity?
How does it work?
Properties of ionic compounds?

6. Ionic or Covalent?
NaCl
NO2
N2Br
NaI
CaS

7. Ionic or Covalent?
KNO3
Fe(CrO4)2
Cu(OH)2
BaI F2

8. Ionic or Covalent? O2
AgCl
AgNO3

9. Covalent Bonding

10. Covalent Bonding two or more non-metals
all with high electronegativity
ions are NOT formed!!
atoms share some valence electrons (not transfer) to make a full octet of 8

11. One e- shared by each atom
usually each atom donates (shares) one of each pair of electrons
Electron Pair
Shared by both atoms
One e- shared by each atom F F

12. octet rule: usually, atoms want 8 valence e- (H, He need 2)
number of bonds formed depends on the number of e- required to fill the valence shell
noble gases = full valence, rarely form compounds
octet rule: usually, atoms want 8 valence e- (H, He need 2)

13. Ex: C has 4 valence e- Ex: F has 7 valence e- Nitrogen? Oxygen?
needs 4 more to form a full octet
C forms 4 bonds
Ex: F has 7 valence e-
needs 1 more to form a full octet
F makes one bond
Nitrogen? Oxygen?

14. Demonstration!
(the return of the little white balls)

15. Properties of Covalent Compounds
covalent bonds = strong
forces between molecules = weaker
covalent molecules are easily separated from one another
soft solids (l or g at room temp)
do not conduct electricity
not very soluble in water
low melting/boiling points (liquid or gas at room temperature)

16. Examples of Covalent Compounds

17. Videos! http://www.youtube.com/watch?v=QqjcCvzWwww

18. Objective: SWBAT name and write formulae for covalent compounds.
6 January 2010
Objective: SWBAT name and write formulae for covalent compounds.
Do Now:
What is the difference between ionic and covalent compounds? (Write at least two complete sentences.)

19. Agenda Seating/success survey Naming covalent compounds
Writing formulae for covalent compounds

20. Announcements Missing work is on bulletin board in 104.
Did you take the Ions and Ionic Compounds test?
Last day to hand in missing work:
Tues. Jan. 12
Midterm: Wed. Jan. 20
10:20 am-12:10 pm

21. How did we name ionic compounds?

22. Naming Covalent Compounds
What do the little numbers (subscripts) mean?!
Subscripts = The number of atoms of each element!!
Use prefixes to communicate how many atoms of each element.

23. Prefix System 1 – mono* 2 – di 3 – tri 4 – tetra 5 – penta
*never use mono if the FIRST element listed in a compound has one atom.
The SECOND element gets an “-ide” ending

24. Write names or formulae
NO2
CO2
PCl5
P2S4
Nitrogen trioxide
Carbon monoxide
Dinitrogen tetrahydride

25. Name these covalent compounds
NH3
CH4
CF4
H2O
P3O5
SBr2
P2O3
What is the ratio of nitrogen atoms to hydrogen atoms in NH3?

26. Write formulae Dinitrogen monoxide Carbon tetrachloride
Oxygen difluoride
Sulfur trioxide
Dichlorine octoxide
Sulfur dibromide
Dioxide difluoride
Xenon tetrafluoride

27. Homework
Week 18 Homework #6-7

28. Objective: SWBAT draw Lewis dot structures for covalent compounds.
7 January 2010
Objective: SWBAT draw Lewis dot structures for covalent compounds.
Do Now:
P2O5
a) Ionic or covalent? Name it.
b) What is the ratio of phosphorus to oxygen?
c) Name one property you would expect this compound to have.

29. Agenda Go over homework (correct it!) How to draw Lewis dot structures
Lots of practice on whiteboards!
Homework: Finish Week 18 Homework – due tomorrow

30. Announcements Missing work is on bulletin board in 104.
Did you take the Ions and Ionic Compounds test?
Last day to hand in missing work:
Tues. Jan. 12
Midterm: Wed. Jan. 20
10:20 am-12:10 pm

31. 7 January 2010
Objective: SWBAT name, write formulae for, and diagram ionic and covalent compounds.
Do Now:
Draw the Lewis Dot Structure for HCN.

32. Agenda Homework answers, collect HW Review stations
Naming ionic and covalent compounds
Formulae of ionic and covalent compounds
Properties
Lewis dot structures

33. F C F F F C F F C F F F F Bonding between C and F
structural hybrid Lewis dot
formula diagram structure
=e- pair F e- C e-
=covalent bond

34. O C O O C O O C O Double Bond sharing two pairs of electrons
bonds more strongly than a single bond
structural hybrid Lewis O C O O C O O C O

35. Triple Bond
Strongest N N N N N N

36. Drawing molecule diagrams
Decide how many bonds each atom makes.
The central atom is the one that makes the most bonds.
Draw with single bonds
Calculate remaining electrons
Use remaining electrons

37. HCN (hydrogen cyanide) HCO2- (methanoate ion)

38. Draw structural, hybrid and Lewis structuresHF
NH3
CH4
CF4
NO2-
CHCl3
NH4+
H2CO
SeF2

39. Names and Formulae All Mixed Up!
These are ionic OR covalent!
If given the name, write the formula
If given the formula, write the name

40. Length and Strength of Bonds
single double triple longest shortest lowest energy highest energy

41. sometimes, a solid lattice is held together with covalent bonds
covalent network (giant covalent structures): very hard, very high melting/boiling points
Examples: diamonds and graphite (both C), SiO2