1. Concept presentation Ionic and Covalent Bonding (SCH3U)
Presenter: Iris Lo
Instructors: Janine Extavour & Marty Zatzman, OISE/UT

2. Overview Curriculum Expectations Common Misconceptions
Curriculum Placement
4 Day Lesson Sequence
Applications
Teacher Resources

3. Curriculum Expectations
Specific Expectations:
B2.1 – Use appropriate terminology related to chemical trends and chemical bonding, including, but not limited to: atomic radius, effective nuclear charge, electronegativity, ionization energy and electron affinity.
B2.4 – Draw Lewis structures to represent the bonds in ionic and molecular compounds.
B2.5 - Predict the nature of a bond (e.g., non-polar covalent, etc.) using electronegativity values of atoms.
B2.6 - Build molecular models, and write structure formulae, for molecular compounds containing single and multiple bonds and for ionic crystalline structures.
B3.4 – Explain the differences between the formulation of ionic bonds and the formation of covalent bonds.
B3.5 – Compare and contrast the physical properties of ionic and molecular compounds.

4. Ideas Covered: Background Information: Bohr’s Model of the Atom
Periodic table
The Basics:
Octet Rule
Drawing Lewis structures
Electronegativity values
Ideas Covered:
Intramolecular bonding (ionic, polar covalent and covalent)
Intermolecular bonding
Metallic bonding

5. Bonding Analogy Welcome to the Dr. Phil Show!
Today we will be counseling 3 divorced couples
Lisa Simpson and Milhouse
Buzz Lightyear and Jessie
Ken and Barbie
Let’s have a look at how they interact to determine what is ‘bonding’ them together before we begin!

6. Couple #1
Milhouse is still very attracted to Lisa while she feels no attraction.
Milhouse has taken sole custody of their child, Nelson, a factor that keeps them bonded together.
Which bond does this couple represent (ionic, polar covalent or non-polar covalent)?

7. Couple #2
Buzz Lightyear is more attracted to Jessie than she is to him.
Although this attraction is unequal, they Do still share a love for one another.
They have joint custody of their son, Buzz Jr, with Buzz Jr. spending time primarily with his father.
Which bond does this couple represent (ionic, polar covalent or non-polar covalent)?

8. Couple #3 This couple has equal attraction to each other
They maintain their bond by having shared custody of their son, Ben.
Ben spends an equal amount of time with both parents.
Which bond does this couple represent (ionic, polar covalent or non-polar covalent)?

9. Common Student Misconception #1
“Since both involve charges, the attraction between polar covalent molecules is the same as the attraction between ions in an ionic compound”
Solutions:
Emphasize that charges across polar covalent bonds are only partial charges
Use the Dr. Phil bonding analogy

10. Common Student Misconception #2
“The Lewis structure of covalent compounds gives the shape of the molecule.”
Solutions:
Reinforce that Lewis structure only shows atom linkage
Have students build molecular models (modification: use gumdrops and toothpicks)

11. Common Student Misconception #3
“When predicting bond type using electronegativity, there is a sharp divide between ionic and covalent bonds.”
Solutions:
Emphasize that the spectrum of electronegativity difference values is smooth
Reinforce using a model of a bonding continuum and a table organizer showing percent ionic/covalent character for various ∆EN values

12. Common Student Misconception #4
“The modern view of the atom is one in which the electrons circle the nucleus in fixed orbits, like the planets orbiting the sun.”
Solutions:
Make students aware that the models they are using is simplified
Chemists describe electrons in terms of energy and probability of finding electrons within a region of space
Use videos to help students visually
Covalent Bonding Video
Ionic Bonding Video

13. Curriculum Placement of the Unit
Matter, Chemical Trends and Chemical Bonding unit:
Matter, Chemical Trends and Chemical bonding unit is placed as the1st unit of the course
Covers underlying basis of all other units
Natural progression from grade 9 and 10 Chemistry
Chemical Reactions suggested to be the 2nd unit
Natural progression from grade 10 Chemistry
Natural progression from Unit 1 - writing chemical formulas and naming of compounds needed for writing chemical equations, predicting chemical reaction products, etc.)

14. Concept Placement Within the Unit
Placed after periodic trends and before writing chemical formulas and naming compounds
Suggested order of the chemical bonding section:
1) Review:
Bohr model of the atom, ion formation, properties of ionic and molecular compounds
2) Introduce key underlying concepts:
Octet rule, Lewis structures
3) Introduce bonding overview:
To give students some context
4) Intramolecular bonds: Ionic and covalent bonding
5) Intermolecular and Metallic Bonding

15. Bonding Overview

16. 4 Day Lesson Sequence Day 1: Review & Classifying Chemical Compounds
PowerPoint presentation:
Bohr model of the atom
Drawing Lewis structures
Properties of ionic and covalent compounds.
Demo:
Test and compare the conductivity of salt solution and sugar solution
Safety: Use low-voltage conductivity apparatus
Group Activity: Bond With a Classmate
Students act as positive and negative ions and form bonds with their peers. Introductory activity for day 2.
Assessment:
Informal question and answer (diagnostic)
Lewis structure and Properties of Ionic/Covalent Compounds worksheet
Predict, Observe, Explain Activity

17. Bond With a Classmate Activity: Your Thoughts?
In your table groups, discuss:
a) Pros/cons of this activity?
b) Ways to modify this activity for:
-Different grade levels
-Different streams (i.e. academic, applied, etc.)

18. Day 2: Introduction to Bonding
PowerPoint presentation:
Octet rule
Electronegativity (including its periodic trend)
Bonding continuum/characteristics of ionic, polar covalent, covalent bonds
Video Clip on Bonding/Electronegativity
Role-Play:
Use the analogy of 3 couples going through relationship counseling to represent ionic, polar covalent and covalent bonding.
Assessment:
Informal question and answer
Determine Bond Type Using Electronegativity worksheet
Observation & feedback

19. Day 3: Ionic and Covalent Bonding
Ionic Bonding
PowerPoint presentation/Chalk and Talk:
Formation of ions,
Transferring single /multiple electrons & bonding involving > 2 ions (shown using Lewis structures/structural formulas),
Properties of ionic compounds.
Demo: Poker chips used to simulate ionic bonding.
Video Clip: Ionic Bonding
Covalent Bonding
PowerPoint presentation (continuation):
Single and multiple covalent bonding (shown using Lewis structures/structural formulas)
Coordinate covalent bonds
Exceeding the octet rule
Properties of covalent compounds
Compare/contrast ionic and covalent compounds.
Demo: Poker chips used to simulate covalent bonding.
Video Clip: Covalent Bonding

20. Day 3 (Cont’d) Assessment: Informal question and answer
Drawing Lewis and Structural Diagrams of Ionic and Covalent Compounds worksheet

21. Day 4: Polar Covalent Bonding
PowerPoint presentation:
Polar covalent bonding (shown using Lewis structures and structural formulas)
Polar/non-polar molecules, partial charges, and overall polarity
Summary of all 3 bonds
Demo:
Place a charged ebonite rod next to water and then hexane. Water (polar) is attracted to the rod, hexane is not (non-polar)
Safety: Hexane is a flammable liquid – do not place near open flames.
Do not directly smell it. Use in well-ventilated area.
Class discussion: Applications and societal implications.
Lab: Gumdrop Molecular Models
Build molecular models and draw the Lewis diagram, structural formulas and predicted shape of molecule for ionic and covalent compounds (Cherkas et al., ).
Safety: Students must not eat the candy if they are working with it in the lab.

22. Day 4 (Cont’d) Assessment and Evaluation:
Informal question and answer (assessment) Polar Covalent Bonding worksheet (assessment)
Predict, Observe, Explain Activity (assessment) Learning skills rubric (assessment)
Lab worksheet (evaluation)

23. Concept Applications 1) Ions and the Human Body
Humans depend on ions for their survival they are essential for maintaining good health
2) Carbon Dioxide in Soft Drinks: A Covalent Compound
CO2 is somewhat soluble in water, especially at high pressures which is why soft drinks are bottled under pressure (Mustoe et al., 2001).
When you open a bottle of pop, some of the CO2 comes out of solution due to its low solubility (Mustoe et al., 2001).
3) Application of Water Polarity: Microwave Ovens
Water is a polar molecule that is a good absorber of microwaves (Rayner-Canham, et al., 2002).
The energy is converted into heat to warm up food (Rayner-Canham, et al., 2002).

24. Resources
1) Nelson and McGraw-Hill Ryerson Chemistry 11 Teacher’s Resource
Both provide:
background info
teaching suggestions (activities, tips/safety precautions for conducting labs, effective ways to approach the topic)
answers to lab/textbook questions
common misconceptions and solutions
Prefer McGraw-Hill Ryerson Teacher’s Resource
more detailed, includes strategies to support diverse student needs (ex. ESL students, etc.)

25. Resources (cont’d) 2) Chemistry Games: J. Hand’s class website
Provides pre-made review games
3) Chalkbored: J. Schneider’s class website
Provides PowerPoint presentations, handouts, labs, worksheets for grade 11 and 12
4) Chemistry Demonstrations: T. Sperring’s website
Provides many quick Chemistry demos
Materials, procedure and what should be observed are included

26. References
1) Cherkas, A., Freure, C., George, T., Ivanco, J., Kisway, L., Plavetic, S.J., Stewart, J., and G. Wisnicki. (2002). McGraw-Hill Ryerson Chemistry 11 Teacher’s Resource. Toronto: Mc-Graw-Hill Ryerson. 2) Hand, J. (2010). Chemistry Games. Retrieved July 9, 2010, from < 3) Jenkins, F., van Kessel, H., Davies, L., Lantz, O., Thomas, P., and D. Tompkins. (2002). Nelson Chemistry 11. Toronto: Nelson Thomson Learning. 4) Jenkins, F., van Kessel, H., Davies, L., Sanader, M., Tompkins, D., Lantz, O., and S. Haberer. (2002). Nelson Chemistry 11 Teacher’s Resource. Toronto: Nelson Thomson Learning. 5) Mustoe, F., Jansen, M., Doram, T., Ivanco, J., Clancy, C., and A. Ghazariansteja. (2001). McGraw-Hill Ryerson Chemistry 11. Toronto: McGraw-Hill Ryerson Limited. 6) Rayner-Canham, G., Damju, S., and U. Goering-Boone. (2002). Addison Wesley Chemistry 11. Toronto: Addison Wesley. 7) Schneider, J. (2009). Chalkbored: Chemistry 11. Retrieved July 9, 2010, from < 8) Sperring, T. (2000). Chemistry Demonstrations. Retrieved July 9, 2010, from < ce/Chemistry%2520Demonstrations+water,+ebonite+rod,+hexane&cd=1&hl=en&ct=clnk&gl=ca>