1. Smells Unit – Investigation IV
Polar Bears and Penguins

2. Admit Slip (cont.) Consider the following illustration:
Draw the Lewis dot structure for HCl.
If the penguin represents a hydrogen atom and the polar bear represents a chlorine atom, what does the ice cream represent in the drawing? What do you think the picture is trying to illustrate?
(cont.)
Unit 2 • Investigation IV

3. Agenda Admit Slip Comic Book Questions Exit Slip
Product: Questions, Exit Slip
Homework: Draw picture on last page!
Unit 2 • Investigation IV

4. You will be able to: Recognize and explain a polar bond.
Unit 2 • Investigation IV

5. Activity
Purpose: In this lesson you will be exploring polarity and bonding between atoms in greater detail. A comic book will provide new information about these topics and will introduce you to the concept of electronegativity, which helps us to understand partial charges.
Unit 2 • Investigation IV

6. Classwork : Complete questions
Classwork is due at:
Unit 2 • Investigation IV

7. Making Sense What does electronegativity have to do with polarity?
Unit 2 • Investigation IV

8. Exit Slip Would hydrogen fluoride (HF) have a polar bond? Explain why.
How would the H and F atoms be portrayed in the comic book—as polar bears, penguins, or both? Explain.
Draw the partial charges next to the H and F atoms.
Draw a dipole arrow for the bond.
Unit 2 • Investigation IV

9. Wrap-Up
Anytime there are two different types of atoms sharing electrons, there will be a partial negative charge on one atom and a partial positive charge on the other atom.
Electronegativity measures the tendency of an atom to attract the electrons in a bond.
(cont.)
Unit 2 • Investigation IV

10. (cont.)
The bonds are labeled nonpolar covalent, polar covalent, and ionic as the difference in electronegativity between the two atoms in the bond increases.
Unit 2 • Investigation IV