1. Bell Work p.263 CO2 H2S Draw these Lewis Structures and name the shape
PCl3
CO2
H2S

2. Name their shapes and bond angles
Trig. pyramidal
PCl3
CO2
H2S
Linear
Bent

3. Today Molecule shapes and angles review Electronegativity (EN)
Polarity

4. Draw Lewis structures and name the shape (p. 263)
PCl5 HI
AlCl3
SF6
Trig. bipyramidal
Linear I
Trig. planar
octahedral

5. I e-! An element’s ability to attract electrons in a chemical bond
p. 194
Electronegativity (EN)- what is it?
Write YOUR definition of EN on your board
An element’s ability to attract electrons in a chemical bond

7. Where’s the e- party?

8. Why do Ionic bonds transfer e- and Covalent bonds share?
If big difference (>1.7) in EN= ionic
Li= 0.98
F= 3.98
= 3.0
IONIC Li F
F has enough “power” to take an e- from Li

9. Why do Ionic bonds transfer and Covalent bonds share?
If small difference (<0.4) in EN= covalent (N2)
N=3.04 =0
Neither N has enough power to take an e-, so they share

10. What if they share e- , but unequally?
If medium difference ( ) in EN= POLAR covalent
H= 2.20
Cl= 3.16
= 0.96 + -
+pole
-pole

11. Electronegativity (Recap)
big difference (>1.7) in EN= ionic
small difference (<0.4) in EN= covalent
medium difference ( ) in EN= POLAR covalent
Difference in EN
Range
Bond Type
Big
>1.7
Ionic
Medium
Polar covalent
Small
<0.4
Covalent

12. Calculate Diff. in EN and find if ionic, polar covalent or non-polar covalent (PT on p. 265)OH F2
LiCl H2
=1.24 Polar covalent
=0 non-polar covalent
= 2.18 ionic
=0 non-polar covalent

13. How can we determine whether a molecule is polar or nonpolar?
Electronegativity
______________
And the
________________
POLAR Molecules are _____________
And
Nonpolar Molecules are ______________
Shape
Asymmetric
Symmetric

14. POLAR= asymmetrical
Non-polar=symmetrical

15. Draw it and determine P or NP?
NH3
CCl4
H2S
PCl3
Br2

16. Exit Slip
What does it mean when we say a molecule is polar?

17. Bellwork
Electronegativity (EN)= How strongly an atom attracts ________ in a bond.
__________ is the most EN on the PT
If one atom has a much higher EN, it will unequally share e- polar e- F

18. Linear 180o NP 107.3o P Bent 104.5o P Trig. planar 120o NP
Shape Name
Bond <
P or NP
Linear
180o NP
Trig. pyramidal
107.3o P
Bent
104.5o P
Trig. planar
120o NP

19. Today Polarity Review Lewis structures Properties Bending Water lab
How does soap work?
What is surface tension?

20. Linear 180o NP 107.3o P Linear 180o P 109.5 NP Trig. pyramidal
Shape Name
Bond <
P or NP
Linear
180o NP
Trig. pyramidal
107.3o P
Linear
180o P
Tetrahedral
109.5 NP

21. Draw it! P or NP?
C2H4
CH3CH2CH3

22. H-H
H-I
C=O
O=O
H-F
P-H
F-F

23. Draw a Water Molecule (Lewis) Label the – and + poles

24. Water Balloons
Hold your balloon about 1” away from a THIN stream of water
Draw a picture of what happened, using a water molecule - - - - ?

25. Water is POLAR

26. Why does water “bead” together?
Positive (+H) poles attract negative poles (-O)

27. Why does oil float on water?
“Like dissolves Like”
Polar dissolves in polar
Non-polar dissolves in non-polar
Oil, grease, fat= non-polar
Water= polar

28. How does soap work? Article-”How does soap dissolve grease?” Lab-
Petri dish with oil drops
Beaker with soapy water
Q-tip
Article-”How does soap dissolve grease?”
Read article, then write an explanation for how soap breaks up grease into smaller particles-(5 sentences)

29. Exit Slip
Draw carbon tetrachloride, name its shape, bond angle and polar or non-polar