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Activity Book 3: Secondary Level

The activities in this section are applicable for individuals aged 16 and up.

  1. Electrolysis
  2. Fuel Cell
  3. Exploring Acids and Bases
  4. Polymers as Molecules
  5. Make a Slimy Polymer
  6. Balloon Trick
  7. A Simulated Martian Greenhouse
  8. Catch a Falling Ruler
  9. That's easy for you to say
  10. Breads of the world
  11. Land size conversions and comparisons
  12. Answer Key: Future Fuels: Exploring Electrochemistry with Electrolysis and Fuel Cells
  13. Answer key: Martian greenhouse
  14. Answer Key: That's Easy for You to Say
  15. Answer Key: Breads of the World
  16. Answer Key: Land size conversions and comparisons

Electrolysis

National Research Council Canada

Learning Objectives:

Students will:

  • Perform electrolysis of brine (a solution of sodium chloride)
  • Write the electrode and balanced oxidation-reduction equations for electrolysis of a brine solution
  • Identify the tools and materials used and show the direction of flow of electrons during electrolysis of brine
  • Explain the process of electrolysis

Teaching Strategies:

  • Construct electrical circuits
  • Experimentation involving data collection and analysis
  • Balancing oxidation-reduction equations

Materials Needed (Per Group)

  • Distilled water - 150 mL
  • Table salt (NaCl) - 15 mL
  • 5 mL measuring spoon - 1
  • 250 mL glass beaker - 1
  • Platinum-coated electrodes (or carbon electrodes) - 2
  • Electrical wire with alligator clips - 3 black, 3 red
  • Power supply (rectifier) or 9-volt battery - 1
  • Voltmeter - 1
  • Watch with a second hand or stopwatch - 1
  • Safety goggles - 1 pair per person

Question: Can a salt solution be taken apart by electricity?

Procedure

Step 1

Copy the observation chart on the next page in your science journal or notebook.

Observation chart
Step Voltage (V)
Step 3
Step 4
Step 6 - 5 mL
Step 7 - 10 mL
Step 7 - 15 mL

Step 2

Put on safety goggles.

Step 3

Pour 150 mL of distilled water into the glass beaker. Connect the voltmeter and power source to the electrodes so that they form parallel circuits. Put the electrodes into the water. They can be resting gently on the bottom. Set the voltmeter to the 0-20 VDC range.

Do not switch on the power supply yet. What voltage is observed? Record your observations on the chart.

Step 4

Next, switch on the power supply. What voltage is observed? Record your observations on the chart.

Step 5

Switch off the power supply and hold the electrodes out of the water. Slowly add 5 ml of table salt to the water and stir gently to dissolve the salt. The water will be cloudy at first, but should eventually clear. This is now brine (a salt solution).

Step 6

Put the leads into the brine and switch on the power supply once more. Now what voltage is observed? Record your observations on the chart. Describe what is happening at the cathode and at the anode. Record your observations in your science journal or notebook.

Step 7

Without switching off the power supply, add an additional 5 mL of salt and stir. Now what voltage is observed? Add the remaining 5 mL and repeat the observations.

Step 8

In your science journal or notebook, write the electrode and balanced oxidation-reduction equations for the chemical reactions which occurred in this activity.

Observations and Conclusions

  1. Why is salt added to the water?
  2. Why do you think that no bubbles were produced before the salt was added?
  3. What do you observe happening in the beaker after the salt has been added?
  4. How does the higher concentration of salt affect the voltage? Why do you think this is?
  5. What are the bubbles made of? Why do you think this?
  6. How could you determine experimentally what the gases are that are produced at the cathode and anode?
  7. Did you smell something during the experiment? What could that have been?
  8. Label the drawing of the apparatus to the right. Be sure to include the cathode, anode, electrodes, electrolyte (brine), voltmeter and power supply. Also show on your diagram the direction of flow of electrons.

Discussion

  1. What evidence is there that water can be taken apart by electricity?
  2. Explain the process of electrolysis, using this experiment as an example.
  3. Define oxidation and reduction. What is being oxidized and what is being reduced in this experiment?
  4. How do the oxidation-reduction equations explain what you observed during the experiment?
  5. Is distilled water a good electrolyte? Why or why not? What about tap water?
  6. What are the potential applications of electrolysis?


Extended Activities

Repeat the experiment using different liquids, such as diluted orange juice (or other citrus juice), tap water, tap water and sulfuric acid, vinegar, etc. How do the voltages compare to those of the salt solution? Write the balanced oxidation-reduction equations for each liquid tried.

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Fuel Cell

National Research Council Canada

Learning Objectives:

Students will:

  • Create an elementary fuel cell from a brine solution
  • Write the electrode and balanced oxidation-reduction equations for reverse electrolysis of a brine solution
  • Explain the process of reverse electrolysis
  • Explain how electrical energy is produced in a hydrogen fuel cell

Teaching Strategies:

  • Experimentation involving data collection and analysis
  • Balancing oxidation-reduction equations

Materials Needed (Per Group)

  • Distilled water - 150 mL
  • Table salt (NaCl) - 15 mL
  • 5 mL measuring spoon - 1
  • 250 mL glass beaker - 1
  • Platinum-coated electrodes (or carbon electrodes) - 2
  • Electrical wire with alligator clips - 3 black, 3 red
  • Power supply (rectifier) or 9-volt battery - 1
  • Voltmeter - 1
  • Watch with a second hand or stopwatch - 1
  • Safety goggles - 1 pair per person

Question: Can gas molecules react to produce electricity?

Procedure

Step 1

Switch off the power supply. Try not to bump the beaker so that as many gas bubbles as possible remain attached to the electrodes.

Step 2

Now that the power source is no longer supplying electrons, electrolysis is no longer occurring. Is electricity being produced? Complete the chart below in your science journal or notebook.

Observation chart
Time (s) Voltage (V)
0
30
60
90
120
150
180
210
240
270
300

Record the voltage immediately after turning off the power source (0 s) and at 30 second intervals for 5 minutes. You may need to switch the voltmeter to a more sensitive setting as this is happening.

Step 3

Write the electrode and balanced oxidation-reduction equations for reverse electrolysis of brine in your science journal or notebook.

Step 4

After recording your observations, remove the electrodes from the brine and detach them from the alligator clips. Disconnect all wires and pour out salt solution. Wash glassware and put all materials away.

Observations and Conclusions

  1. What is happening at the cathode and the anode?
  2. What did you observe about the voltage over time? Why do you think that this pattern occurs?

Discussion

  1. What evidence is there that electricity is produced when water is put back together?
  2. Explain the process of reverse electrolysis, using this experiment as an example.
  3. What is being oxidized and what is being reduced in this experiment?
  4. How do the oxidation-reduction equations explain what you observed during the experiment?
  5. What type of electrochemical cell is this gas battery?
  6. How is a fuel cell different from a storage battery?
  7. What are some of the potential applications of this experiment?

Extended Activities

  1. Repeat the experiment using different metals for electrodes, such as iron nails, rolled up aluminum foil or graphite pencil leads. How do the voltages compare to those of the salt solution?
  2. If you tried different electrolytes in the previous experiment, remove the power source from the electrolytes to find out if they produce electricity and, if so, how much?
  3. What are the benefits and drawbacks to this type of energy source?
  4. Where can people obtain hydrogen to use in fuel cells?
  5. The National Research Council has an institute dedicated to fuel cell research. To find out more about this research and to help with the Fuel Cell Challenge, go to http://www.nrc-cnrc.gc.ca/eng/ibp/ifci.html
  6. Where else is fuel cell research happening in Canada?
  7. What would be the advantages of hydrogen fuel cells over other sources of energy?
  8. How will technology need to change in order to make fuel cells a practical source of energy?
  9. If a power source is needed to produce the hydrogen which is used for the fuel cell, then how does this make any ecological sense? How could hydrogen be produced in a renewable way?

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Exploring Acids and Bases

National Research Council Canada

Frequently, chemists refer to materials as being either an acid or a base.

In order to determine if a material is acidic or basic (alkaline), chemists use a pH Indicator -- pH stands for "potential of hydrogen". A pH Indicator expresses how acidic (like an acid) or basic (like a base) a substance is. pH is indicated by a numbered scale: A pH of 7 is neutral. A pH below 7 denotes acidity while one above 7 denotes alkalinity.

In these experiments, students will make a pH indicator using red cabbage and investigate the properties of several materials found around the home.

Materials:

  • one red cabbage
  • water
  • white vinegar (acetic acid)
  • window cleaner (ammonia)
  • baking soda (sodium bicarbonate)
  • washing soda (sodium carbonate)
  • lemon juice (citric acid)
  • antacids (calcium carbonate, calcium hydroxide, magnesium hydroxide)
  • seltzer water (carbonic acid)
  • soft drink

Preparation of the Red Cabbage Indicator:

  1. Place about half a red cabbage cut into 2.5-centimeter (1-inch) cubes into a pan and add about 750 millilitres (3 cups) of water
  2. Boil on high heat for about 10 minutes.
  3. After the water has cooled, strain the mixture through a sieve.
  4. The resulting strained liquid, from the red-cabbage extract, is our pH Indicator that we will used to explore the world of acids and bases.

Establish the pH range:

  1. Pour 50ml (1/4 cup) of vinegar (acetic acid) into a colourless drinking glass. Add 1/2 teaspoon of red cabbage extract, stir the mixture, and note the colour.
  2. Pour 50ml (1/4 cup) of window cleaner (ammonia) into a colourless drinking glass. Add 1/2 teaspoon of red cabbage extract, stir the mixture, and note the colour.
pH Range
Approximate pH Colour of extract
2 red
4 purple
6 violet
8 blue
10 blue-green
12 green

Procedure:

Add 1/2 teaspoon of red cabbage to the following and record your observations:

  1. baking soda (sodium bicarbonate, NaHCO3)
  2. washing soda (sodium carbonate, Na2CO3)
  3. lemon juice (citric acid, C6H8O7)
  4. antacids (calcium carbonate, calcium hydroxide, magnesium hydroxide)
  5. seltzer water (carbonic acid, H2CO3)
  6. soft drink

Scientific Note:
The pH number is the negative exponent of 10 representing hydrogen ion concentration in grams per litter. For
instance a pH of 7 represent 10-7 grams per litter. i.e. pH = (log10{1/[H+]}).

Consequently each whole pH value below 7 is ten times more acidic than the next higher value. For example, a pH of 4 is ten times more acidic than a pH of 5 and 100 times (10 times 10) more acidic than a pH of 6. The same holds true for pH values above 7, each of which is ten times more alkaline -- another way to say basic -- than the next lower whole value. For example, a pH of 10 is ten times more alkaline than a pH of 9.

Note: Activity adapted from multiple sources by NRC scientist Dr. Mike Day.

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Polymers as Molecules

National Research Council Canada

Before you begin, ask your students the following questions:

  1. "What are Polymers?"
  2. Have the students look around the room and see what materials they can recognize as polymeric or plastic materials.
  3. Help them in distinguishing between natural polymers and synthetic polymers.

Demonstration: Build a series of polymer molecules

Materials:

  1. Polystyrene craft balls (large and small sizes)
  2. Toothpicks or skewers

Procedure

  1. Construct a simple molecule of methane (CH4) using one large ball and 4 small balls. Explain that methane is made up of one simple single carbon atom and four hydrogen atoms. STSE link: methane is natural gas used to heat many homes in Canada.
  2. Add 3 balls to your methane molecule to construct a simple molecule of ethane (C2H6). STSE link: ethane is a still a simple molecule and is still a gas.
  3. Add 3 more balls to create the molecule propane (C3H8). STSE link: propane is still a gas and is used as the Fuel in many BBQs.
  4. Add 3 balls again to create the molecule butane (C4H10). STSE link: butane is now a liquid, and is commonly used in BBQ lighters.

Using the large balls that represent carbon atoms, you can illustrate the structure of many other molecules based upon carbon and hydrogen. Explain to the students the importance of chain length on properties and what they represent in every day life.

  • carbon balls = octane, the major component in gasoline
  • 8 carbon balls = octadecane, a grease used in Vaseline
  • 8 carbon balls = octacosane, a solid that is the main component in candle wax

To become a polymer, anywhere from 1,000 to 10,000 balls need to be joined to this chain. You can use a long beaded necklace or length of beaded string to illustrate this concept. A polyethylene garbage bag would have polymer chain that is at least 10 times this length.

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Make a Slimy Polymer

National Research Council Canada

What are Polymers?

A polymer is a large molecule composed of repeating structural units, connected by chemical bonds. While many people think of polymers as plastics, the term actually refers to a large class of natural and synthetic materials with a variety of properties. The word "polymer" comes from Greek: "poly" means many and "mer" means parts. Most polymers are based upon carbon.

This is a hands experiment in which the students make their own slime.

Materials:

  1. Cornstarch
  2. Warm water
  3. White glue
  4. Green food colouring
  5. Container or jar with tight-fitting lid
  6. ZipLock® baggies

Procedure:

  1. Make a cornstarch solution by adding 1/8 cup of cornstarch to a 1/2 litre of warm water in a jar (smaller quantities 1/2 teaspoon cornstarch in 2 tablespoons of warm water). Shake until most of the cornstarch dissolves and let cool
  2. Place 2 teaspoons of white glue into a baggie. Add 2 drops of green food coloring.
  3. Add 2 teaspoons of water close the baggie tight and mix to give a uniform colour.
  4. Now add to the baggie 1 spoonful of the cornstarch solution, close the baggie tight and then squish the baggie to mix once again.

You have now prepared green slime...how revolting!

Recommendation: When working with larger groups, it is helpful to prepare the solution and baggies ahead of time.

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Balloon Trick

National Research Council Canada

Materials:

  1. Balloons
  2. Wooden skewers
  3. Cooking oil
  4. Black magic marker

Procedure:

  1. Inflate a balloon until it's nearly full size and then let about a third of the air out. Tie a knot in the end of the balloon.
  2. Carefully examine the balloon. Notice the thick area of rubber at both ends of the balloon (where the knot is tied and at the opposite end).
  3. Dip the tip of a wooden skewer into the cooking oil, which works as a lubricant.
  4. Place the sharpened tip of the skewer on the thick end of the balloon and push the skewer into the balloon. Be careful not to jab yourself or the balloon with the skewer. Just use gentle pressure (and maybe a little twisting motion) to puncture the balloon.
  5. Push the skewer all the way through the balloon until the tip of the skewer touches the opposite end of the balloon (at the other thick portion.) Keep pushing until the skewer penetrates the rubber.
  6. Breathe a huge sigh of relief and take a bow! Ta-Dah!
  7. Gently remove the skewer from the balloon. Of course, the air will leak out of the balloon, but the balloon didn't pop.

Repeat the experiment again, this time illustrating the hidden "stress" in a balloon.

  1. Before blowing up the balloon, draw about 10-15 dots on the balloon with the magic marker. The dots should be about the size of the head of a match. Be sure to draw them at both ends and the middle of the balloon.
  2. Inflate the balloon half way and tie the end. Observe the various sizes of the dots all over the balloon. Judging from the size of the dots, where on the balloon are the latex molecules stretched out the most? Where are they stretched out the least?
  3. Carefully examine the wooden cooking skewer. Dip the tip in the vegetable oil and use your fingers to coat the skewer with oil.
  4. Use the observations that you made previously with the dots on the balloon to decide the best spot to puncture the balloon with the skewer without popping it.

How does it work?

The secret is to uncover the portion of the balloon where the latex molecules are under the least amount of stress or strain. After drawing on the balloon with the marker, you probably noticed that the dots on either end of the balloon were relatively small. You've just uncovered the area of least stress... the ends of the balloon. When the point of the skewer is positioned at the ends of the balloon, the solid object passes through the inflated balloon without popping it.

If you could see the rubber that makes up a balloon on a microscopic level, you would see many long strands or chains of molecules - a polymer!. The elasticity of these polymer chains causes rubber to be stretchy. Blowing up the balloon stretches these strands of polymer chains. Even before drawing the dots on the balloon, you probably noticed that the middle of the balloon stretches more than either end. You wisely chose to pierce the balloon at a point where the polymer molecules were stretched out the least. The long strands of molecules stretched around the skewer and kept the air inside the balloon from rushing out. When you remove the skewer, you feel the air leaking out through the holes where the polymer strands were pushed apart. Eventually the balloon deflates... but it never popped.

Just to prove the point, try pushing the skewer through the middle part of an inflated balloon. The experiment will go out with a bang!

Note: All activities adapted from multiple sources by NRC scientist Dr. Mike Day.

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A Simulated Martian Greenhouse

Canadian Space Agency

Begin by reviewing the following steps, paying close attention to any special instructions and warnings.

Set up a journal in which to record all details related to the construction of your simulated Martian greenhouse and in which to record any observed changes that occur in your greenhouse from day to day and week to week.

Step 1

To build a simulated Martian greenhouse we need to find a large empty wide-mouth jar (with a lid), like the kind used by restaurants for Heinz ketchup and mustard.

Begin by preparing the soil. The bottom layer should consist of a thin layer of gravel covered with a layer 2-3cm thick of charcoal. These layers act as soil and air buffers to help reduce large swings in the moisture content, and chemical composition, of the atmosphere in your simulated Martian greenhouse.

For root support the top layer of the soil should consist of a layer of peat moss. (For a more realistic Martian soil-simulation, a mixture of sterile sand and clay can be substituted, but its water retention properties are much less than that of peat moss).

Finally, plant an assortment of small green plants, or alternately, plant a few tomato seeds.

Step 2

Once the plants are installed you may wish to wait a few days to allow the plant roots to establish themselves in their new environment before proceeding to this step.

Prepare the rim of the jar with a light coat of vacuum grease or with a strip of Teflon plumber's tape so that the lid can be installed immediately after the carbon dioxide has been poured into the jar.

To create a carbon dioxide atmosphere we will simply pour carbon dioxide (whose density is greater than that of air) into the jar.

A simple source of carbon dioxide can be obtained by reacting a generous quantity of ordinary baking soda (sodium bicarbonate) with a generous quantity of cold vinegar (diluted acetic acid) in a very large container. Allow the reaction to subside, then carefully pour the carbon dioxide (which is denser than air) into the greenhouse.

Step 3

The last step before screwing down the lid is to use a pair of tongs to insert a hot (120°C) bar of charcoal (which has been oven heated for at least one hour) into the jar. SEAL IMMEDIATELY!

Oven heating the bar of charcoal drives moisture and gases out of the bar. As the bar cools it will absorb an enormous quantity of carbon dioxide and will significantly reduce the gas pressure within the jar.

Step 4

The thin layer of vacuum grease (or Teflon ribbon) provides an airtight seal which preserves the low gas pressure within the jar, simulating a low pressure carbon dioxide Martian greenhouse atmosphere.

CAUTION: A sealed glass container should always be handled carefully.

Your simulated Martian greenhouse begins with a slight negative pressure of mostly CO2 but the pressure can drop dramatically because of carbon dioxide's very high solubility in water.

Water on the other hand evaporates very rapidly under low pressure conditions. If your jar is left in a sunny or hot environment the pressure inside can rise well above normal atmospheric pressure, resulting is an exploding jar!

Always wear eye protection and gloves when handling your micro-ecosystem.

Alternative to Step 2

If a compressed CO2 cylinder is available then CO2 can be added directly into the jar to displace the oxygen and nitrogen inside.

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Catch a Falling Ruler

Canadian Space Agency

Work in a group of three. Choose a subject, a recorder and a team leader.

Trial #1

  1. The subject sits in a chair, extends her/his arm forward and supports the elbow with the opposite hand.
  2. The team leader places a 30 cm ruler upright between the subject's thumb and index finger so that the 0 mark on the ruler is at the upper edge of the subject's thumb.
  3. Release the ruler. The subject catches it. The recorder records the measurement at the subject's thumb.

Trial #2

  1. Repeat the procedure with the subject lying on his/her back. Hold the dominant arm upright and extend the opposite arm across the body and support the elbow.

Trial #3

  1. Repeat the procedure with the subject lying on his/her side with the dominant side up and the arm bend at the elbow and extended outward. Support the arm with the opposite hand.

As a team, compare the results of the three trials.

  • Which position felt most comfortable?
  • Does the response time vary from position to another?
  • What explanation can you suggest for the variance?

Since the astronaut does not have the opportunity to conduct all of his/her work in a typical body positions, how might this affect productivity?

What training can you suggest?

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That's easy for you to say

Statistics Canada

The population of Canada in 2006 was 31,612,897. That was easy to say wasn't it? In a few breaths you have just stated what took years to produce. Have you ever tried to count 31,612,897 people? It's a big job!

It is difficult to describe how big a job it really is to take a census in Canada. In 2006, 25,000 temporary employees were sworn in under the Statistics Act to work for the census. These people were trained, equipped and supervised so that the portrait of Canada from the 2006 Census would be as accurate as possible.

Once all the completed census forms were received in the data processing centre, information from the questionnaires had to be scanned and the long task of analysing, interpreting and publishing the data could begin.

A good way to understand the many aspects of planning, conducting and reporting a survey is to take one yourself.

If you want to conduct a survey in your school, take a look at the checklist of questions that must be answered before you can get it off the ground. Once you've answered these questions, it will be easy to walk up to someone and say, "Hi! I have a few questions to ask you."

Defining the task

  • Do you have permission to conduct a survey?
  • How much time do you have for the whole project? (days, class periods)
  • Will this be a class project or something larger?
  • Will this be a census covering the entire school or a survey of a portion of the school population?
  • Will you collect facts or is this an opinion poll?
  • When and how will you collect the information?
  • What are the major topics you will research and why? (for example, youth issues, school issues)

Designing the questionnaire

  • What type of questions will you use? (for example, multiple choice, fill-in-the-blank)
  • How many topics do you want to include?
  • How many questions will you ask? (If two topics, how many questions per topic?)
  • How many possible answers will there be for each question?
  • Are the questions concise and easy to understand?
  • Do you want to include background questions like name, age, sex, grade, or where the person lives?
  • Will your questions provide the data you are seeking?
  • How are the questions arranged on your form?
  • How will your forms be printed? (Could the school newspaper / office print them?)

Collecting the data

  • Who will answer the questions?
  • Is this a personal interview or is it a self-completed survey?
  • How will you deal with the privacy of the respondent's information if you ask for their names?
  • How will you get everyone to respond?
  • Do you need publicity?
  • What will you do if someone is away or does not answer?
  • How will you make sure that everyone is counted only once?
  • How will you know that all the forms were returned?

Processing the data

  • How will you check the returned questionnaires for completeness?
  • How will you summarize the data? (For example, will you use tables, graphs, or charts?)
  • Is the questionnaire designed to make this easy?
  • Will you be using a computer or tallying by hand?
  • How does the use of one or the other affect the amount of time you need or how much you can ask?
  • How will you check to make sure there are no errors in the processing?
  • If processing is done on a computer, how will you construct the database?
  • If it is done by hand, how will you record the data (on a form, on the chalkboard, something else)?

Reporting the data

  • How will you report the data?
  • What tables do you want to make?
  • Do you want to include graphics, like a bar or pie chart?
  • Would percentages help you communicate the data better?
  • Do you want to write a report about the findings?

Handout: Student survey on future plans

Directions:

For each question, select 1 response. Your answers will be completely confidential; only summary data will be reported.

Thank you for taking the time to complete this survey. Getting your answers and those from others is important in producing accurate data.

1. How old are you?

  1. less than 12
  2. 12
  3. 13
  4. 14
  5. 15
  6. 16
  7. 17
  8. 18
  9. 19
  10. Older than 19

2. What is your sex?

  1. Male
  2. Female

3. What languages do you speak well enough to have a conversation? Write in the "other" language on the line provided.

  1. English only
  2. French only
  3. other(s)
  4. English and French
  5. French and other(s)
  6. English and other(s)
  7. English, French andh.other(s)

4. How many hours did you spend last week working for pay?

  1. under 5 hours
  2. 5 to 9 hours
  3. 10 to 19 hours
  4. over 19 hours
  5. none (go to question 6)

5. In what type of business, industry or service did you work? Write in your answer on the line provided. (Give details. For example: food service industry, childcare, retail sales)

6. After high school, which of the following do you plan to do?

  1. attend a trade school
  2. attend a college or university
  3. join the police / firefighters / member of the military
  4. get a full-time job
  5. travel
  6. none of these

7. Rank the top three occupations you would MOST like to pursue after school. Enter "1" beside your first choice; "2" beside your second and "3" beside your third.

  • truck driver
  • salesperson
  • teacher
  • administrative assistant
  • nurse
  • social worker
  • farmer
  • tradesperson - carpenter / mechanic / electrician
  • web designer
  • childcare worker / babysitter / nanny
  • doctor
  • homemaker
  • fisherperson
  • police officer / firefighter / member of the military
  • stockbroker
  • computer analyst / programmer
  • lawyer
  • artist / cultural worker
  • engineer
  • civil servant
  • businessperson
  • forest ranger
  • chef
  • hairdresser / esthetician
  • writer
  • other

8. Rank the top three occupations you would LEAST like to pursue after school? Enter "1" beside your first choice; "2" beside your second and "3" beside your third.

  • truck driver
  • salesperson
  • teacher
  • administrative assistant
  • nurse
  • social worker
  • farmer
  • tradesperson - carpenter / mechanic / electrician
  • web designer
  • childcare worker / babysitter / nanny
  • doctor
  • homemaker
  • fisherperson
  • police officer / firefighter / member of the military
  • stockbroker
  • computer analyst / programmer
  • lawyer
  • artist / cultural worker
  • engineer
  • civil servant
  • businessperson
  • forest ranger
  • chef
  • hairdresser / esthetician
  • writer
  • other

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Breads of the world

Statistics Canada

People make bread in every country of the world. They mix flour or meal with water or other liquids. They may add a little fat (like oil or butter) and a rising agent (such as yeast) and cook the mixture in a pan or oven. Sharing bread
with guests can be a way to make them feel welcome.

Below are the names of some of the breads we eat here in Canada which come from all over the world. Can you match the name of the bread to its description?

Breads of the world
Home-made breads Answers Country of origin
A. Baguette Ethiopian bread, very thin (teff grain, or millet and barley)
B. Bannock bread from the Caribbean and India (whole wheat)
C. Challah a long thin loaf of French bread (wheat)
D. Injera First Nations’ bread, of Scottish origin (oatmeal or barley)
E. Naan Italian fruit bread for Christmas (wheat or millet)
F. Johnnycake corn bread (corn), an early American staple food
G. Panettone dark rye bread from Eastern Europe (rye)
H. Pita Mexican bread (corn or wheat)
I. Pumpernickel Mediterranean pocket bread (wheat)
J. Roti Jewish egg bread (wheat)
K. Tortilla white bread from India (wheat)

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Land size conversions and comparisons

Statistics Canada

The metric system became standard in Canada in 1977. The metric unit for measuring farmland is hectares.

Using the information below, complete the following table by converting the measurements into hectares and/or square metres. Measure your classroom in square meters. Is the measurement of your school grounds available? If so, enter the number in square meters. Convert both the classroom and the school grounds measurement into hectares.

1 hectare [ha] = 10,000 square metres [m2]

Hectares (ha) Square meters (m2)
Standard prairie field 64.78
Urban lot for a house
Average size of a farm in Canada in 2006 294.74
Average size of a farm in Newfoundland and Labrador in 2006 64.78
Average size of a farm in Saskatchewan in 2006 5,866,400;
Your school grounds
Your classroom

How many classrooms, the size of your current classroom, would fit into 1 ha?

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Answer Key: Future Fuels: Exploring Electrochemistry with Electrolysis and Fuel Cells

Fossil Fuels - Time for a Change

Today, most of the world's energy comes from fossil fuels such as coal, oil and natural gas, and our dependency on these fuels is a global issue. These fuels are not unlimited or renewable, yet demand for energy keeps increasing. In addition, the burning of these fuels fills the air with a cocktail of gases which lead to pollution such as smog and acid rain. Things cannot continue this way forever, which is one of the reasons that more and more researchers and engineers are now exploring various types of clean, renewable energy sources such as solar, wind, waves, biomass and hydrogen.

Hydrogen You Say?

Hydrogen fuel cells are the basis of an exciting and new energy system. The basic principle of a hydrogen fuel cell is a chemical reaction between hydrogen and oxygen which produces water, electricity and heat. One of the ways to obtain hydrogen for fuel cells is from water itself. Water (H2O) can be chemically separated in a process known as electrolysis. Electrolysis is the production of chemical changes by the passage of an electrical current through an electrolyte.

Electrolysis Terminology

  • Electrolysis takes place in what is called an electrolytic cell - The pieces of metal which connect the energy source to the electrolyte are called electrodes.
  • The electrode which is attached to the negative pole of the battery (supplies electrons to the electrolyte) is called the cathode and the electrode which is attached to the positive pole of the battery (accepts electrons from the electrolyte) is called the anode.
  • An electrolyte is an electrically conductive solution containing free ions. When an electric current is passed through an electrolyte, chemical reactions take place at the electrodes.
  • When molecules or positive ions (called cations) come in contact with the cathode, they tend to gain electrons (i.e., they are reduced).
  • When molecules or negative ions (called anions) come in contact with the anode, they can be stripped of electrons (i.e., they are oxidized).

Oxidation-Reduction Reactions

During electrolysis, oxidation and reduction reactions occur. An oxidation occurs when a molecule or negative ion gives up one or more electrons. This reaction occurs at the anode. A reduction occurs when a molecule or positive ion accepts one or more electrons. This reaction occurs at the cathode. In this series of activities, students will perform simple electrolysis, as well as reverse electrolysis, to create an elementary fuel cell. Finally, students will be challenged to design and build a working fuel cell.

Electrolysis Learning Objectives:

Students will:

  • Perform electrolysis of brine (a solution of sodium chloride)
  • Write the electrode and balanced oxidation-reduction equations for electrolysis of a brine solution
  • Identify the tools and materials used and show the direction of flow of electrons during electrolysis of brine
  • Explain the process of electrolysis

Teaching Strategies:

  • Construct electrical circuits
  • Experimentation involving data collection and analysis
  • Balancing oxidation-reduction equations

Fuel Cell Learning Objectives:

Students will:

  • Create an elementary fuel cell from a brine solution
  • Write the electrode and balanced oxidation-reduction equations for reverse electrolysis of a brine solution
  • Explain the process of reverse electrolysis
  • Explain how electrical energy is produced in a hydrogen fuel cell

Teaching Strategies:

  • Experimentation involving data collection and analysis
  • Balancing oxidation-reduction equations

Before performing these activities students should be familiar with the following concepts:

  • Electrical circuits
  • Oxidation-reduction reactions and skills:
  • Setting up a circuit
  • Using a voltmeter

Materials Needed (Per Group)

  1. Distilled water - 150 mL
  2. Table salt (NaCl) - 15 mL
  3. 5 mL measuring spoon - 1
  4. 250 mL glass beaker - 1
  5. Platinum-coated electrodes (or carbon electrodes) - 2
  6. Electrical wire with alligator clips - 3 black, 3 red
  7. Power supply (rectifier) or 9-volt battery - 1
  8. Voltmeter - 1
  9. Watch with a second hand or stopwatch - 1
  10. Safety goggles - 1 pair per person

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Answer key: Martian greenhouse

Objective

Investigate the difficulties in building a stable ecosystem containing higher organisms, such as tomatoes and other green plants, in a relatively small space.

Some important concepts

An Ecosystem: An ecosystem is a community of living organisms interacting with each other and their non-living environment.

community + habitat = ecosystem

For this investigation we will provide a suitably prepared habitat within a sealed glass jar, into which we will place a small community of plants.

Dynamic Equilibrium

The micro-ecosystem in this project contains soil, an atmosphere, green plants, plus innumerable "stowaway" microorganisms.

The only resource that enters and leaves the ecosystem is energy.

The energy balance is important to an ecosystem. When too much energy enters, the temperature will rise until the energy input is exactly balanced by the heat lost. Conversely, when the energy output (as heat) exceeds the energy input to the system, the temperature of the system will decrease until equilibrium is re-established.

In order to achieve stability an ecosystem must attain a state of "dynamic equilibrium". In this state the (average) rate at which resources, such as carbon dioxide, are consumed, is balanced by the rate at which that resource is replaced through the process of recycling.

A Stable Ecosystem

A stable ecosystem is one in which, on average, a state of dynamic equilibrium exists.

Environmental Conditions on Mars

Martian 'soil'

The Martian "soil" is about 40% SiO2 (silicon dioxide), a fine sand-like material and about 20% Fe2O3 (iron oxide) "dust". This dust is very fine, its texture is similar to that of talcum powder.

The remainder of the Martian soil consists of clays, dust, gravel, pebbles, stones and rocks of both simple and complex minerals similar to those found on Earth.

As far as we know, the Martian soil is sterile.

How fertile is the Martian soil? It's hard to say, but based on the results of both Viking landers and the recent Mars Pathfinder missions, the soil appears to be a much better medium for plant growth than most soils on the Earth, although Martian soils appear to be somewhat deficient in potassium.

Martian atmosphere

The atmospheric pressure on Earth is typically about 100kPa (kilopascals). On Mars it is less than 1kPa; far too low for either plants or humans.

Plants can survive with a mere 5 kPa atmosphere, 2kPa nitrogen, 2kPa oxygen, 0.6kPa water vapour, and less than 0.1kPa carbon dioxide and the remainder a mixture of gases such as argon and nitrogen; whereas, humans prefer at least 20kPa of oxygen and 10kpa nitrogen (as a buffer) to work and breathe comfortably (about 30kPa).

In a Martian greenhouse, astronauts will have to wear a space suit.

Temperature

On Mars, even in the equatorial zone, the temperature is perishingly cold; colder than anywhere on Earth, except perhaps during long polar winter nights near the South pole.

To grow plants on Mars a suitable warm environment will need to be created.

Martian greenhouse

Although plants can survive with less than 0.1kPa carbon dioxide they can survive with much more. In fact, most green plants prefer a carbon dioxide-rich atmosphere. On Mars, a greenhouse would not necessarily have to be a closed ecosystem. It is assumed that on Mars the atmospheric pressure and atmospheric composition within the greenhouse could be adjusted using outside resources. For example, excess methane gas could be vented outside of the greenhouse and perhaps more carbon dioxide could be added by extracting it from the Martian atmosphere, pressurizing it, and pumping it into the green house.

Similarly the amount of water and fertility of the soil could be adjusted using outside resources.

Tips for a successful martian greenhouse

  • Since your greenhouse is on the Earth, solar irradiation is quite high, therefore it is best not to expose your greenhouse to direct sunlight for more than an 5 or 10 minutes or so per day.
  • Stand or lay a small thermometer (the kind you see for attaching to coat zippers) in your ecosystem where it can be easily seen.
  • Place a small piece of Litmus paper in your ecosystem so that you can monitor changes in the acid-base level of moisture within your ecosystem.
  • A small amount (approximately 10-20 grams) of steel wool, washed with alcohol and rinsed with clean fresh water (to remove grease) and then mixed with the soil will not only remove excess oxygen from your greenhouse (rendering the atmosphere in the jar more Mars-like), it will also add iron oxides to the soil (making the soil more Mars-like too.)
  • Plants adapt well to most light and temperature conditions (within a reasonable range), but they do not adapt well to frequent changes in their environment. Keep your Martian greenhouse in the same location, well lighted, and at a fairly constant temperature.
  • Try to avoid "standing" water in your greenhouse. Before you add the carbon dioxide atmosphere check that the soil is moist, but not saturated, and that the inside bottom of the jar is just wet enough that water does not run from side to side within the jar when it is tilted.
  • A few drops of liquid indoor-plant fertilizer added to the jar, according the manufacturer's directions, will help stabilize the plants in their new environment.
  • If you use the vinegar and baking soda method to produce carbon dioxide you will notice that it produces a large amount of foam and mist. Be careful not to inadvertently allow any of the foam or mist to enter your greenhouse jar.

Plan an investigation

Experience has shown that in a sample of ten or twelve micro-ecosystems (a class set), some will survive only a few weeks, others will last a few months, and rarely, a few will survive more than a year.

The challenge is to determine, if possible, the reasons for the abrupt failure of some and the remarkable success of others.

A class discussion on this topic will elicit as many hypotheses explaining the failure/success of their greenhouse simulators as there are students. This provides an excellent opportunity to have students invoke the Scientific Method and to have them design further experiments to test their hypothesis.

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Answer Key: That's Easy for You to Say

Overview

This activity uses hands-on experience to demonstrate many aspects of planning, conducting and reporting the results of a survey.

Students will learn what goes into the production of statistical information, how individual responses on a questionnaire are merged to create summary data, and how the summarized information is used.

This activity could take the form of a full count of the student body. If this is too ambitious, a small survey or an opinion poll of a sample of the student population or specific class may be more appropriate. Use topics of interest to students and teachers.

Since the census takes place in May 2011, schedule the completion of this activity or parts of it (data collection) in May. If you intend to have the students conduct a survey or census, remember to allow yourself enough lead time.

Duration:

Two or three class periods if students use the prepared questionnaire in Handout 2 (https://www12.statcan.gc.ca/census-recensement/2011/dp-pd/index-eng.cfm ).

or

Four or five class periods if students create their own survey using the information provided in Handout 1 ( https://www12.statcan.gc.ca/census-recensement/2011/dp-pd/index-eng.cfm ). This would include:

  • two class periods before conducting the survey;
  • one period collecting the data; and
  • one or two periods after collecting the data. (Times will vary with the complexity of the questionnaire and the size of the group surveyed.)

Note: See the Teacher's Guide (https://www12.statcan.gc.ca/census-recensement/2011/dp-pd/index-eng.cfm ) for general background on the census and census vocabulary.

Learning objectives

  • Understand the stages of designing, conducting and processing a survey.
  • Learn how to design, conduct, process and report on a survey.
  • Learn how to write a report analysing the results of a survey.
  • Learn how to work as a team to reach mutually agreed decisions and to resolve issues.

Vocabulary

census, complete count, confidentiality, data, enumeration, questionnaire, sample, survey, undercount

Getting started

  1. Ask your students to write down what they think the population of Canada was in 2006. Give them a moment to do so and then write the figure on the chalkboard. (Answer: In 2006, the population of Canada was 31,612,897.)
  2. Ask several of the students to comment on how their estimates compared to the actual figure.
  3. Ask students how they think the 2006 population figure for Canada was determined. (Answer: Every five years Statistics Canada conducts a census - a complete count of the country's population.)
  4. Ask the class to concentrate again on the 2006 population figure. Ask them to estimate the time it took to produce this figure. Now distribute Handout 1 for all to read.

Note: The 2006 Census took place in May 2006. The population counts were available in March 2007.

Census activity

1. Discuss the stages of the survey process listed on Handout 1. You may wish to show a flow chart such as the one below, listing the questions from the handout underneath each stage.

  • Define
  • Design
  • Collect
  • Process
  • Report

2. This is the point at which the class should decide whether they want to plan and conduct their own survey or use the questionnaire in Handout 2. If the class decides to use the prepared questionnaire in Handout 2, continue with the rest of item 2 and end the lesson. If the class decides to create their own survey, skip to item 3.

  • Distribute Handout 2: Student survey on future plans.
  • Before students answer the prepared questionnaire, have them discuss how they will tabulate their results and what they will want to report. Ask them to consider what summary information they would like to analyse and what their tables (columns, rows, etc.) will look like. Ask students to identify interesting questions that summary data could answer. For example: "Do male and female students in the class have the same career goals?" To answer this question they must be able to cross-tabulate question 2 with question 7. This can be a long job if the tabulating is done by hand. Manual tallying may limit them to looking at the simple frequencies for single questions, such as "How many hours did you spend last week working for pay." Access to a computer will provide greater flexibility.
  • Have the students answer the prepared questionnaire. Ask the class to follow through on their processing and reporting strategies for Handout 2.
  • The class may wish to conduct the same survey with a larger group to learn how the data compare with the whole grade or the whole school. How students process the data, what they report, and how much time they have will dictate the response here.

3. If the class is conducting their own survey, have them re-examine the full range of questions in Handout 1. Some key questions to consider are:

  • How big will the project be?
  • Who will be surveyed?
  • What will they be surveyed about?
  • How much time will the class invest in conducting, processing and analysing the survey?
  • Will the results be shared?
  • How will you protect confidentiality?

Distribute Handout 2: Student survey on future plans. This prepared questionnaire may be used as a model for the survey form that the class will design. Ask students to consider the merits of the prepared questionnaire by taking note of its concise questions, its multiple-choice format, and the low number of open-ended questions.

Ask students to consider the merits of the prepared questionnaire by taking note of its concise questions, its multiple-choice format, and the low number of open-ended questions.

Teacher hints

If the students design their own survey, limit the number of questions to about 10.

Avoid fill-in-the-blank (open-ended) type questions in favour of questions where answers may be checked or circled.

Include several "demographic background" items so that students can correlate data and make statements such as "Female students are most likely to say..."

Try to focus the survey on student and school concerns.Take time to test the questionnaire through role-playing or a small sample test to ensure that the questions make sense and provide useful answers.

Try to make the survey part of some larger event such as a display, special assembly or open house so students can see that other people are interested in the survey results.

Note: Be sure that the survey has been approved / registered in advance by your school's administration. https://www12.statcan.gc.ca/census-recensement/2011/dp-pd/index-eng.cfm

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Answer Key: Breads of the World

Overview

This activity introduces students to the Census of Agriculture. Students will appreciate the value of agriculture in today's society and its effect on their lives. Three activities, which provide a detailed picture of Canada's most important primary industry, are available for various grade levels.

Students will examine sets of imaginary data associated with several community services, decide which neighbourhoods would benefit most from each service, and illustrate their findings on a grid map.

Note: See the Teacher's Guide for general background on the census and census vocabulary. More information on the Census of Agriculture is provided in this activity under the section Census of Agriculture. You may wish to review this information with you students before starting the activities. https://www12.statcan.gc.ca/census-recensement/2011/dp-pd/index-eng.cfm

Getting started

Using the background information provided in the Teacher's Guide, tell students about the census and let them know that Canada's next census takes place in May 2011.

Explain to your students that there are two types of censuses: a Census of Population and a Census of Agriculture. The Census of Agriculture is taken at the same time as the Census of Population to find out about the country's farming and food production.

In May 2011, each agriculture operation in Canada will receive a Census of Agriculture questionnaire in the mail. The Census of Agriculture collects a wide range of data on the agriculture industry. More information on the Census of Agriculture can be found on pages 5-6.

Learning objectives

  • Develop a knowledge of agriculture and its role as a primary industry.
  • Understand the impact agriculture has on every resident in Canada.
  • Appreciate that statistics represent real people and their actions.

Census activity

Distribute Handout 1: Breads of the world. Have students match the bread name to its grain and country of origin. This activity is suitable for elementary, intermediate and senior grade levels.

People make bread in every country of the world. They mix flour or meal with water or other liquids. They may add a little fat (like oil or butter) and a rising agent (such as yeast) and cook the mixture in a pan or oven. Sharing bread with guests can be a way to make them feel welcome.

Below are the names of some of the breads we eat here in Canada which come from all over the world. Can you match the name of the bread to its description?

Breads of the world
Home-made breads Answers Country of origin
A. Baguette D Ethiopian bread, very thin (teff grain, or millet and barley)
B. Bannock J bread from the Caribbean and India (whole wheat)
C. Challah A a long thin loaf of French bread (wheat)
D. Injera B First Nations' bread, of Scottish origin (oatmeal or barley)
E. Naan G Italian fruit bread for Christmas (wheat or millet)
F. Johnnycake F corn bread (corn), an early American staple food
G. Panettone I dark rye bread from Eastern Europe (rye)
H. Pita K Mexican bread (corn or wheat)
I. Pumpernickel H Mediterranean pocket bread (wheat)
J. Roti C Jewish egg bread (wheat)
K. Tortilla E white bread from India (wheat)

Answers: D, J, A, B, G, F, I, K, H, C, E

To expand on this activity, ask the students to bring in samples of the grain products listed in Handout 1.

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Answer Key: Land size conversions and comparisons

History

The Census of Agriculture is taken at the same time as the Census of Population to find out about the country's farming and food production.

Agriculture is an important part of our economy. Jean Talon's census of 1667 tells us that the colony had 11,448 arpents of land (3,915 hectares) under cultivation, 3,107 cattle, and 85 sheep.

A mid-decade agricultural census was first held in Manitoba in 1896.

When the provinces of Saskatchewan and Alberta were created in 1905, the increasingly rapid settlement of the west made the quinquennial census a constitutional requirement. A new Census and Statistics Act called for additional censuses of population and agriculture to be taken in the provinces of Manitoba, Saskatchewan and Alberta in 1906 and every 10 years after that until the population of each of the three provinces reached 1.25 million. These censuses continued until 1956, when Canada began taking national censuses of population and agriculture every five years.

New in 2011

In May 2011, each agriculture operation in Canada will receive a Census of Agriculture questionnaire in the mail. The Census of Agriculture collects a wide range of data on the agriculture industry such as number of farms and farm operators, farm areas, business operating arrangements, land management practices, livestock numbers and crop areas, operating expenses and receipts, farm capital and farm machinery and equipment. These data provide a comprehensive picture of the agriculture industry across Canada every five years at the national, provincial/territorial and sub-provincial levels.

Users of Census of Agriculture data

Census of Agriculture data are used by various organizations for many reasons:

  • operators use census data to make production, marketing and investment decisions. They can also keep abreast of trends in Canadian agriculture through the analysis of Census of Agriculture data published by the agriculture media.
  • producer groups and marketing agencies use census data to tell Canadians and government how they are doing economically through their non-government organizations.
  • companies supplying agricultural products and services use the data to determine where to locate their service centres.
  • government policy advisors use the data to help develop programs related to safety nets and human resources for the agriculture sector.
  • operators can keep abreast of trends in Canadian agriculture through the analysis of Census of Agriculture data published by the agriculture media.
  • agriculture websites can target their information to current trends and needs in the sector based on census data.

Vocabulary

  • Census of Agriculture: an enumeration of every farm, ranch or other agricultural operation with sales of agricultural products during the year prior to the census. Held every five years in conjunction with the Census of Population, the Census of Agriculture asks questions about land use, crops, livestock, agricultural labour, farm income, and land management practices.
  • Biotechnology: a science that relates biology to technology
  • Census farm: an agricultural operation producing at least one agricultural product for sale
  • Diversification: giving variety to, expanding into different fields
  • Hectare: the metric unit for measuring farmland. One hectare equals 10,000 square metres.
  • Net farm income: net income (gross receipts from farm sales minus depreciation and cost of operation) earned by working for oneself (self-employment) as an owner/operator of his/her farm.
  • Non-farm work: (formerly called off-farm work) the number of days farm operators worked away from the farming operation at paid agricultural and non-agricultural work.

Activity 5: Answers to Handout 4

Hectares (ha) Square meters (m2)
Standard prairie field 64.78 647,800
Urban lot for a house 0.09 900
Average size of a farm in Canada in 2006 294.74 2,947,400
Average size of a farm in Newfoundland and Labrador in 2006 64.78 647,800
Average size of a farm in Saskatchewan in 2006 586.64 5,866,400;
Your school grounds*
Your classroom*

* The size of the classroom and school grounds should be measured in square metres.

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