Homework for All Grade 7 Classes

Please complete the review questions on pages 208-209. This will help you prepare for the test on Monday or Tuesday for 7D.

You can access these review questions through the online textbook. The instructions for accessing the textbook are in a post just below.

7.2 Check and Reflect

Key Concept Review

1.       Explain why a solid substance occupies less space than the same substance in gaseous form.

The particles in a solid are closer together since they have stronger forces of attraction. The weaker forces of attraction in gases allow them to move further apart.

2.       Explain why the particles of a liquid are able to pour into a container and then take on the shape of that container.

The forces of attraction in liquids are weaker than solids so the particles can move past each other. However, they are not free enough like gases to fill any space they are in.

3.       Explain what happens to the particles of a substance that changes state from liquid to gas.

The energy added to the particles causes them to speed up so fast, that the forces of attraction between them cannot hold them together. They break apart and form a gas.

4.       Explain why ice cubes placed in your refrigerator’s freezer section become smaller over time.

The air circulating in the freezer causes the ice cubes to sublimate. The air picks up frozen water and turns it directly into water vapour.

Connect Your Understanding

5.       Use the particle theory of matter to explain how the particles in an ice cube differ from the particles in a glass of water.

Ice: particles are vibrating, stronger forces of attraction, less space between particles, cannot move freely, keeps its shape

Water: particles are moving faster, weaker forces of attraction, more space between particles, particles can move past each other, takes the shape of its container

6.       Use the particle theory of matter to explain what happens to the particles in a hot drink when it cools down.

The particles in the hot drink lose energy to the surrounding air and the cup or mug it is in. The fast moving drink particles speed up the slower moving air particles and cup particles. This slows the drink particles down.

7.       Use the particle theory of matter to explain why heat is required to boil water.

Energy is needed to speed up the particles and overcome the forces of attraction.

Chapter 7 Review Quizzes

The following quizzes can be used for review:

7.1 Quiz

https://sciencesource.pearsoncanada.ca/quizzes/quiz_07_1BOmTe.htm

7.2 Quiz

https://sciencesource.pearsoncanada.ca/quizzes/quiz_07_2b3Xn9.htm

Also, it would be wise to access the textbook online and work on the Check and Reflect questions on pages 198 and 206. As well as the Chapter Review on pages 208-209.

How to Access the Textbook Online

You must first log in to www.sciencesource.ca

1. Select the Grade 7 Textbook
2. Select "Log in" on the left side
3. Enter the log in: ClassFollower
4. Enter the password: Follower
5. Select the unit you would like to study; we are now working on Unit C
6. The first or second link at the top of the page should bring you to Chapter 7

Grade 7 Test Postponed until Monday.

Based on the results of the review today, we need to go over some concepts before testing. You may still have a quiz this week, but the test won't be until next week.

Links for Review

Particle Theory

http://resources.yesican-science.ca/lpdd/g07/lp/nelson/nel07.html

Change of State

http://www.saburchill.com/chemistry/chapters/chap033.html

Three States of Matter (click the images for animations)

http://web.visionlearning.com/custom/chemistry/animations/CHE1.1-an-threestates.shtml

Key Term Matching

https://sciencesource.pearsoncanada.ca/resources/gr7_matchquiz_ch07/

Labelling Practice

https://sciencesource.pearsoncanada.ca/resources/gr7_labelquiz_ch07/

Chapter 7 Quiz

http://wps.pearsoned.ca/ca_school_ontarioscience_7-8/102/26140/6692048.cw/content/index.html

Hints for Studying

Be sure to review the worksheets in the package to help support your understanding. The note-taking sheets about particle theory will be helpful.

Grade 7 Chapter 7 Study Guide

Chapter 7 Study Guide

Classes 7A, 7B, 7C, 7D have their test on Thursday February 19th
Class 7E has their test on Friday February 20th.

Key Terms

·         change of state

·         condensation

·         deposition

·         dissolve

·         evaporation (vaporization)

·         freezing (solidification)

·         gas

·         heat

·         heterogeneous

·         homogeneous

·         kinetic energy

·         liquid

·         matter

·         mechanical mixture

·         melting

·         mixture

·         particle

·         particle theory of matter

·         pure substance

·         solid

·         solidification

·         solution

·         sublimation

·         temperature

Please review the following:

1. Classifying mixtures: pure substances and mixtures, heterogeneous and homogeneous mixtures, provide examples of these substances
2. Review the "pure substances: worksheet in the package
3. The changes of state and the diagram in the package; review which changes of state require heat and which require heat to be removed to occur
4. Understand how and why substances change state according the the particle theory
5. The difference between heat and temperature
6. Review the motion and behaviour of particles in solids liquids and gases

More Videos About the Particle Theory (viewed in class)

Measuring Temperature




Evaporation and Condensation

Growth Mindset Videos

Your Brain is Plastic (SciShow)




Neuroplasticity (Sentis)

Pure Substances and Mixtures Information Video

Answers to Pure Substances Worksheet

Pure Substances

1. A pure substance and a mixture could be confused because they are both homogeneous in appearance.

2. They are both the same because they are made of the same particles. Many factors can be tested but their results will always behave the same no matter where they come from.

3. b) Jewelry is not pure gold because pure gold is a very soft. The necklaces the can be bought at a store are a mixture of gold and something else to make it stronger (an alloy). Karats are a measure of the purity of the gold; 24 karats is the highest purity for jewelry.

4. If the shirt has a label with 100% cotton then this is not a pure substance because there will be dyes and other materials (logo design materials) that make up the shirt. 

Section 7.1 Notes

Classification of Matter by Composition

Matter – anything that has mass and takes up space

Mass – the amount of matter in the object (grams, Kg)

Volume - the amount of space that matter occupies (m³, mL)

Solid - matter that has a definite shape and volume.

Particles are vibrating in place, but they cannot move freely.

Liquid – matter that does not have a definite shape but does have a definite volume; a liquid takes the shape of its container.

Particles can move freely past each other, however, they remain in a fixed volume.

A gas is matter that does not have a definite shape or volume.

Gas particles can move freely and fill the spaces they are in.

Pure substance – a substance made up of only one type of matter; e.g., sugar, distilled water, copper wire are all pure substances. Pure substances appear uniform or homogeneous; this means that every part of the substance has the same composition as every other part.

Mixture – a substance made up of two or more different substances; e.g., pizza, soft drinks, eggs. Each substance inside the mixture keeps its own properties; e.g., you can’t see the sugar in soft drinks, but you can taste it.

Classifying Mixtures – mixtures can be grouped into 2 major categories; mechanical mixtures and solutions.

Mechanical mixtures – the different parts of the mixture can be seen; the mixture does not have the same properties throughout.

Sometimes, it’s easy to see the different types of matter throughout the mixture; e.g., snack mix; sometimes you need a microscope.

These mixtures are said to be heterogeneous, this means that it is made up of different substances with different appearances and properties.

Solutions – these mixtures have the same appearance throughout, but they are made up of two or more substances. Solutions are made when you dissolve one substance into another.

All solutions are said to be homogeneous mixtures because they look the same throughout even though they are made up of different substances; e.g., dissolving sugar in tea.

Particle Theory Videos

Particles in Solids





Particles in Liquids