Thermal Energy Transfer Videos Viewed in Class

Answers to the Expansion and Contraction Worksheets

 Solids Expanding and Contracting in our Daily Lives

1. Why is it important to place gaps at regular intervals in sidewalks?

In the summer the sidewalk expands and in the winter it contracts. The gaps allow space for the expansion and contraction so the sidewalk doesn’t crack.

3. Concrete and steel expand at almost the same rate. Explain why this is important in the construction of tall buildings.

If they did not expand and contract at the same rate, there would be many cracks in the building and it might fall down.

Gases Expanding and Contracting in our Daily Lives

1. Explain how a hot air balloon is lifted from the ground.

When the gas particles inside the hot air balloon are heated, they expand and some escape from the bottom of the balloon. This causes there to be fewer air particles inside the balloon then outside the balloon. The less dense hot air will float on more dense cold air so the balloon rises.

c) Once in the air, the burner is turned off and the balloon drifts along with the wind. What will eventually happen to the air inside the balloon?

Cooler air will enter the balloon and the air inside will become more dense. The balloon will begin to go down.

Liquids Expanding and Contracting in our Daily Lives

1. A bowl of hot soup was left on the table to cool. After a few minutes, the amount of soup in the bowl appeared to have decreased? Why?

The soup may have cooled down and there seems to be less soup because the particles become closer together (contract) and become denser.

2. When manufacturers pack liquids into bottles and jars, they leave a small space at the top before putting on the lids. Why?

The space allows for the liquid to expand without causing the bottle to break.

3. Mercury expands and contracts faster than alcohol. Which liquids would be better in a thermometer?

Mercury will tell the temperature faster, but it will also contract faster so it will drop more quickly making it harder to read the temperature. Also, mercury is poisonous!

Hot Air Balloon Video Viewed in Class

Eureka Videos Viewed in Class

Chapter 8 Test Study Guide

Chapter 8 Test Study Guide

Chapter 8 Key Terms

□   alloy
□   concentrated solution
□   concentration
□   dilute solution
□   insoluble
□   saturated solution
□   saturation point
□   solubility
□   solute
□   solvent
□   supersaturated solution
□   unsaturated solution

□   universal solvent

□   rate of dissolving

Separation Methods

□   filtration

□   magnetism

□   evaporation
□   flotation
□   distillation
□   paper chromatography
□   sifting
□   settling

□   sorting

□   separation funnel

□   picking out with tongs

Areas to Review

1. What factors affect the rate of dissolving? How do these factors affect the rate of dissolving?
2. How can a solution be made more concentrated or less concentrated?
3. What are the 2 different meanings of the term “solubility”? (There is a qualitative and quantitative definition)
4. Calculate the concentration of of a solution in grams/100 mL and describe it as a concentrated or dilute solution
5. Complete the check and reflect questions in Chapter 8. They will be taken up in class.

Remember! you can access the textbook online from home!

Chapter 8 Review Activities

Here are some review activities and crosswords to help you study.

Section 8.1 Quiz

https://sciencesource.pearsoncanada.ca/quizzes/quiz_08_1XJ85P.htm

Section 8.2 Quiz

https://sciencesource.pearsoncanada.ca/quizzes/quiz_08_2jTk44.htm

Section 8.3 Quiz

https://sciencesource.pearsoncanada.ca/quizzes/quiz_08_3pvz04.htm

Chapter 8.1 Crossword

http://www.sciencesource.ca/puzzles/puzzle_08_1/

Chapter 8.2 Crossword

http://www.sciencesource.ca/puzzles/puzzle_08_2/

Chapter 8.3 Crossword

http://www.sciencesource.ca/puzzles/puzzle_08_3/

Chapter 8 Matching Quiz

http://www.sciencesource.ca/resources/gr7_matchquiz_ch08/

Chapter 8 Labeling Quiz

http://www.sciencesource.ca/resources/gr7_labelquiz_ch08/

Separating Mixtures Labeling

http://www.sciencesource.ca/resources/05_sep.swf

A good explanation of chromatography (be sure to click "show labels")

http://www.sciencesource.ca/resources/gr7_label_page228.swf

A good explanation of dissolving

http://www.sciencesource.ca/resources/gr7_label_page221.swf

Separating Mixtures

http://www.bbc.co.uk/bitesize/ks3/science/chemical_material_behaviour/compounds_mixtures/revision/9/

Filtration Worksheets Due on Monday April 4th

Please submit all completed worksheets for the filtration project on Monday April 4th.