Grade 5 Science
Core Unit: Heat

Unit overview:

This unit develops the concept of heat as a form of energy. Temperature is one of the criteria used to estimate the quantity of heat energy. The other major component of the unit is the concept of heat transfer, and the application of the principles of heat transfer to energy conservation.

Related units:

The grade 3 Core Unit, Properties of Matter, and Optional Units, Fire and Fuels and Heating and Cooling, all prepare students to deal with the concepts in this unit.

Forms of Energy, a grade 4 Core Unit deals with the nature of heat and some of its effects.

This unit is intimately related to the grade 5 Core Unit on Resources since it is through the renewable and nonrenewable resources that most of the heat on the Earth is produced. It would be most profitable to integrate these two units.

The grade 6 Unit Energy in Our Lives extends the second theme of this Core Unit, heat transfer and energy conservation.

Suggested themes:

conservation, heat, heat transfer, conservation, energy, environment, matter, resources, temperature

Factors of scientific literacy which should be emphasized:

Common Essential Learnings foundational objectives which should be emphasized:

To develop an understanding of how knowledge is created, evaluated, refined and changed within science. (CCT)
To strengthen students' understanding of heat and heat transfer through applying knowledge of numbers and their interrelationships.(NUM)

Science foundational and learning objectives:

Describe the nature of heat.
1. Investigate the effects of heat energy on matter.
2. Explain the kinetic molecular theory.
3. Measure the temperature of various substances.
4. Recognize some sources of heat energy.
Describe the transfer of heat energy.
1. Contrast conduction, convection, and radiation of heat energy.
2. Identify methods of heat conservation in buildings.

Suggested Activities:

Fill three pails with water. To one, add ice so that the temperature of the water is close to 0 °C. Mix tap water and hot water so that the temperature in another pail is about 30 °C. The remaining pail should contain water at about 55 °C. Each group should have a thermometer, two cups, and a jar with at least three times the capacity of the cups. The best cups for this activity are styrofoam cups or insulated mugs. (If you are going to use styrofoam cups, salvage them after they have been used for coffee or hot chocolate. Avoid buying new styrofoam cups since the foaming agent may damage the ozone layer, and styrofoam is not biodegradable. If you can't discourage others from using them, reuse the ones they discard.)
Add water until one cup is about two-thirds full, and mark that level on the side of the cup. Pour the water into the other cup and mark the level on that cup. Discard that water. From the supply pails, fill one cup to the mark with hot water, and the other with cold water. Record the temperature of the water in each cup. Each member of the group should predict what temperature will result when the water from the two cups is mixed. Have students record their predictions. Then pour the contents into the jar, swirl the jar for a few seconds to mix the water, and record the final temperature.
Check the final temperature with the predictions. If one group member is within 3 °C of the final temperature, that member should explain to the group how the prediction was made. Empty the jar and repeat the procedure. Monitor the groups to see how the predicting is coming.
Repeat, using warm water and hot water, and then cold water and warm water. Compare and discuss the predictions and the final temperature.
Produce one more cup which is calibrated to hold the same volume as the two original cups. Get two cups of hot water and one cup of cold water. Measure the temperature of the water in each cup. Each member of the group should predict what temperature will result when the three cups of water are mixed, and record that prediction. Then have students pour the contents into the jar, swirl the jar for a few seconds to mix the water, and record the final temperature. Check the final temperature with the predictions.
Repeat, using two measures of cold water and one measure of hot water.
What would be the resulting temperature if ten measures of hot water at 50 °C were mixed with one measure of water at 0 °C, or if 1 000 measures of hot water at 50 °C were mixed with one measure of cold water at 0 °C?
Factors: B8, B10, C3, C4, C8, C12, E3, E7, E10, F3, G1, G2
Objectives: 1.1, 1.3
Assessment Techniques: 1, 3, 5, 9
Common Essential Learnings: Numeracy. Students measure temperature and predict what will happen when different volumes of water at different temperatures are mixed. The accuracy of their predictions may increase with experience. There is a relationship between the temperature change, the total volume of water mixed, and the quantity of heat contained. Some students may be able to determine that relationship.
Fill a jar about two-thirds full of hot water (around 50°C) and another jar with a similar amount of ice water. Allow the jars to sit on the desk without being bumped for about one minute, to let any currents subside. Measure and record the temperature of the water in each container. Add one drop of food colouring to each jar. Describe the patterns and speedof diffusion of the dye through the water in each jar. Discuss what is observed. Interpret the observations based on the kinetic molecular theory of matter. (At higher temperatures, the water molecules have a greater average kinetic energy. Water molecules at the higher temperature collide at a greater rate with the molecules of dye. This permits the dye to diffuse faster through the water.)
This activity may also be performed as a demonstration by using two petri dishes instead of jars. Place them on an overhead projector, add the water to each jar, then proceed as described in the main activity above. Using the overhead projector makes this an effective way to demonstrate the phenomenon of diffusion to the class. The disadvantage is that in this method students have fewer opportunities to manipulate equipment.
Factors: B13, C2, C3, C8, F2, F3, G1, G2
Objectives: 1.1, 1.2, 1.3
Assessment Techniques: 1, 3, 5, 7c
Common Essential Learnings: Critical and Creative Thinking. Students make careful observations and discuss those observations with others. They strengthen their perceptual abilities, investigating the effects of diffusion on the dye. Inferences regarding the kinetic molecular theory of matter can be made during this activity.
Construct a thermal expansion demonstration. Get a solid aluminum or iron rod from 40 cm to 1 m in length. Support it horizontally with two blocks of wood, with one end of the rod against a wall. Use a drinking straw (the ones with the scoop end distributed with slush drinks are ideal) so that the free end of the rod rests on the end (scoop end) of the straw. A pin pushed through the straw about 3 cm from the point where the straw and rod meet and into another block will act as a pivot for the straw indicator. A reference scale drawn on cardboard may be mounted to the back of the block which supports the straw. Heat the rod, using alcohol burners or candles, and watch the free end of the straw for any movement.
Ask the students to find out what they can about expansion joints used in bridge construction, sidewalk construction, and other areas. How do power lines illustrate thermal expansion and contraction?
Factors: B13, C3, C4, C8, D1, E3, E7, F3, G1
Objectives: 1.1, 2.1
Assessment Techniques: 1, 3, 5, 7c
Common Essential Learnings: Numeracy. Students are able to measure a very small change by the use of amplification.
Get a wide-mouthed large glass jar, like a restaurant-size pickle jar. Put it in a freezer or outside if the temperature is below freezing, so that the air inside the jar is cold. Immediately upon bringing it out of the fridge or while it is still outdoors, cover the mouth of the jar with a piece of a latex examination glove (available from a veterinary supply store) stretched as tightly as possible. Secure the cover with an elastic or string around the neck of the jar. Observe what happens to the latex as the air in the jar warms. Account for this phenomenon. Try heating the jar by placing it in a shallow pan of hot water. Then cool the jar by placing it in a pan of ice water or snow. What effect do these changes have on the latex seal?
An alternate way to demonstrate the expansion of air when heated is to put an empty 2 litre plastic pop bottle in the fridge. Remove it from the fridge and place a small, previously inflated, well-stretched, balloon over the mouth. Ensure that the balloon seals tightly. Place the bottle in a pail of hot water and observe.
Discuss the observations of the expansion of air, using the kinetic molecular theory. Ask students to find examples where the principle of thermal expansion or contraction of gases is used for a particular purpose.
Ask students to notice the explosion symbol and to read the warning on an aerosol can. Have individuals explain through a journal writing activity why the can may explode if heated. Encourage students to make reference to the kinetic molecular theory in their explanation.
Factors: B13, C3, C8, E3, E7, F2, G1
Objectives: 1.1, 1.2
Assessment Techniques: 1, 3, 5, 7c
Common Essential Learnings: Critical and Creative Thinking. The most important part of this activity is having students try to relate what they observe to the kinetic molecular theory of matter. They should be able to make inferences about what might be happening to the atoms of the substance, based on changes which happen to the whole bar.
From a coat hanger, cut a piece of wire about 30 cm to 40 cm in length. Sand off any paint or coating on the wire. Dip the wire in melted paraffin so that 10 cm at one end is left uncoated. Get a similar length of 10 or 12 gauge copper wire (used for house wiring -- the gauge is written on the outer insulation of the cable) and coat all but 10 cm at one end with paraffin. Make sure that the paraffin starts the same distance from the end of each wire. Use a pencil point to make a mark every one cm along the waxed part of the wire.
Construct a stand so that the wires can be supported horizontally about 10 cm above the table top, so that the unwaxed end protrudes about 5 cm. Using candles of the same height, diameter, and wick length, heat the wire at the unwaxed end. Record the time at which each cm mark in the wax melts so that it can't be distinguished. (The first mark should be the 11 cm mark. Which marks remain can be easily checked at any time during the experiment by using a ruler for reference.)
Compare the time it takes for the heat to be conducted along each wire to melt the wax. The data could be represented on a bar graph, with a separate bar for each cm mark. A line graph is better, with length on the vertical axis and time on the horizontal axis. Remember that scales on graph axes, whether bar or line graphs, are segments of number lines.
Another variation, which will show heat transfer through metal is to place drops of wax from a lit candle on a bar or a wire at regular intervals along its length. Place thumb tacks on the hot wax before it has cooled. Heat the bar at one end. As the heat travels along the bar, the wax will begin to melt and the thumb tacks will fall off the bar.
Factors: B8, B13, C3, C11, E3, E7, F3, G1
Objectives: 1.1, 2.1
Assessment Techniques: 1, 3, 5, 7c
Common Essential Learnings: Numeracy. The main emphasis in this activity should be on obtaining the data and preparing the graph. By comparing the graphical information for the different types of wire, students can make inferences regarding the ability with which the different materials conduct heat.
Have a contest to see which group can design and build the best "solar energy trap." The main criterion for judging is the temperature inside the trap after a one hour exposure to sunlight. Other criteria might include such things as design considerations, the cost of the materials, the length of time the trap holds the heat after being removed from the sun, and so on.
Have the students brainstorm to suggest some uses for such a device. They may also investigate the types of solar collectors which are available commercially, and the uses made of them.
A related project is to monitor the temperatures inside parked cars on a sunny day. Perhaps permission can be obtained to use several of the teachers' cars for this project. Different locations within the car, such as the trunk, floor level in the back seat, dashboard or rear window, could be used. The interior temperatures could be compared with the exterior temperature. The thermometer should be shielded so that the sun does not strike it directly.
Factors: A3, B12, B13, C4, C11, D1, E3, E7, E10, G1, G2
Objectives: 1.1, 1.3, 1.4, 2.2
Assessment Techniques: 1, 2, 3, 4, 5, 8, 9
Common Essential Learnings: Independent Learning. Students are faced with a wide variety of learning experiences in this activity. Working individually or in groups, they will come up with a wide variety of solutions to this challenge.
Use a candle to heat a beaker of water. Place the candle so that it is under the centre of the beaker. Make sure that the beaker is one which is approved for heating liquids (pyrex, for example). Use a wire screen between the flame and the bottom of the beaker to diffuse the flame. An interesting side investigation is to look at how the flame is diffused by the screen. Add some flakes of black pepper or a pinch of powdered charcoal to the beaker and observe the currents in the water. Move the candle flame to one side of the beaker to determine if this has any effect on the currents.
Repeat the procedure, using canola oil instead of water. Compare the observations made in each trial.
(Caution: Do not heat the liquids past 50 °C. Hot liquids can cause severe scalds.)
Factors: B13, C3, C4, C11, E3, E7, E10, F2, F3, G1
Objectives: 1.1, 1.3, 1.4, 2.1
Assessment Techniques: 1, 3, 5, 7c

Common Essential Learnings: Critical and Creative Thinking. Students should examine the particles trapped in the currents to see if they are moving in any particular direction.
Measure out equal masses of some stones, some washers, some copper wire, some glass beads, and any other solids which can be heated in water. Small bags of nylon window screening can be made to contain each solid, using a string to tie them together at the top. Leave enough string attached to be used as a handle.
Get one jar or cup for each of the substances in the bags. Select the size of jar or cup so that it will hold sufficient water to cover the sample of solid without overflowing due to displacement. Half-fill each jar with water which is at room temperature or slightly below. Obtain a container of hot water large enough to hold all the sample bags. Place the sample bags in the hot water with the string handles hanging out over the edge. Leave the bags in place for five to ten minutes so that the solids reach the same temperature as the water.
After this time, measure and record the temperature of the hot water, and the water in the jars or cups. Remove the sample bags, one at a time, and place into one of the jars or cups containing the room temperature water. Measure and record the maximum temperature in each cup. Compare the temperature change produced by each substance. Which substance contains the most heat? Which substance contains the least heat? Each group should compare its data with that of the other groups. What would be the final temperature produced by mixing 75 g of water at the same temperature as the solids with the room temperature water sample? What would be the final temperature if cooking oil were used?
Factors: B8, B13, C3, C4, C8, C11, E3, E7, E10, F2, F3, G1
Objectives: 1.1, 1.3, 1.4
Assessment Techniques: 1, 3, 5, 7c, 9

Common Essential Learnings: Critical and Creative Thinking. In this activity students undertake a wide range of experiences to investigate phenomena related to heat transfer.
Do a heat conservation survey of your school. List some of the design considerations for energy efficiency used by architects, and use those to produce a checklist or questionnaire which can be used to complete the survey. The survey can include both objective and subjective criteria. What type and thickness of insulation is present in the walls and ceilings? Are there double entry systems at each door from outside, or do the doors open directly into the hallways? Do the windows shut tightly or do they allow drafts? How comfortable are the classrooms in both extremely cold winter weather and in the hot spells of May and June?
The questionnaire can be revised to produce one for other public buildings in your area, and another for homes. What are the advantages and disadvantages of building to conserve heat?
Factors: A3, B13, B12, C3, D1, F2, F3, G1, G2
Objectives: 1.4, 2.1, 2.2
Assessment Techniques: 1, 2, 3, 4, 5, 6, 9

Common Essential Learnings: Independent Learning. Students have the opportunity to investigate efficient use of energy in buildings. The open-ended nature of this activity allows for diversity.

Grade 5 Science Core Unit: Heat