Summary
In this lesson, students observe the movement of heat energy by measuring the rise in water temperature after placing hot metal washers in the water. Students also calculate the amount of heat energy transferred between the washers and water. Lastly, students cite specific evidence to refute or agree with two claims.
Essential Question(s)
What factors affect heat energy transfer?
Snapshot
Engage
Students engage in a hands-on demonstration of perceived hot and cold using three pans of water of different temperatures. Students use the I Think/We Think strategy to discuss the demonstration.
Explore
Students watch a short clip of heat transfer and make a hypothesis. Students design their own experiments to observe the transfer of heat between two types of matter, thus testing their hypotheses.
Explain
Students explain their procedures, share data, and state their conclusions.
Extend
Students create extensions of their experiments and perform the experiments again.
Evaluate
Students complete Two-Minute Papers in which they refute or agree with a statement, citing specific evidence from their experiments.
Materials
Three pans
Water
Heat Transfer Activity Lab Sheet (attached)
Foam cup
Thermometers
Scientific calculators
Metal washers
Pipe cleaners
Lab notebook
Hot plate
Timers or stopwatches
Sticky easel pad paper
Markers
Colored pencils
Pencils/pens
Sticky notes
Engage
Set up the following demonstration: One pan of ice water, one pan of room-temperature water, and one pan of hot water. Put the pans in that order. Call on a student to place his/her left hand in the cold water and his/her right hand in the hot water. After 30 seconds, ask the student to submerge both hands in the lukewarm water. Ask the student to share his/her observations with the class. Allow other students to participate in the demonstration. If possible, set up enough stations for every student (or small groups of students) to participate.
Say to students: The water in the middle is room temperature. To your hand, under normal circumstances, you may describe it as lukewarm or neither hot nor cold. What happened?
Allow the students to share their ideas.
Give students the following two statements: (1) Heat energy is transferred from objects with low temperatures to objects with higher temperatures. (2) Heat energy is transferred from objects with high temperatures to objects with lower temperatures.
Divide the room into two groups: those who agree with statement one will stand on one side of the room while those who agree with statement two will stand on the other side. Group two to three students together. Make sure they agree with the same statement (are from the same side of the room).
Use the I Think/We Think strategy. Have students first discuss and justify their belief, and then ask the entire group to devise one "we think" statement, justifying their reason for agreeing with the scenario.
Explore
Keep the groups of two to three together.
Show the Youtube video, Red Hot Nickel Ball in Water. It is very short. Be prepared to replay it at least once.
Have the groups to reevaluate their "we think" statements after watching the video. Give them a few minutes for discussion. Instruct the students to make a hypothesis about the transfer of heat between the metal and the water. They must understand that this hypothesis will be tested in an experiment.
Lay out all the materials on a table (washers, pipe cleaners, thermometers, and foam cup). Instruct each group to devise a procedure that will test their hypothesis. They will record their procedure in their lab notebooks.
Explain
Before the students share their data, instruct them to calculate the amount of heat energy actually transferred. The students will have the temperature difference of the water, and the mass of water will be equal to the amount of water they used.
Give each group a poster board. Instruct them to create a poster that displays their experiment. Have the class participate in the Gallery Walk strategy to view and give feedback on one another's posters.
Extend
Ask students: What are ways to change this experiment so that heat transfer is shown more broadly? Then have students create their own extensions of their experiment, write a new hypothesis and procedure, and perform it again.
Upon completion of the extensions, lead a class discussion of all the factors that will affect heat transfer.
Evaluate
Write or post the following statements: (1) Heat energy is transferred from objects with low temperatures to objects with higher temperatures. (2) Heat energy is transferred from objects with high temperatures to objects with lower temperatures. Pair the students. The students will choose one statement. It doesn't matter which statement. They will write a Two-Minute Paper that refutes statement one, citing specific evidence from both of their experiments or a Two-Minute Paper that supports statement two, citing specific evidence from the experiments.
Lastly, write or post the statement: Heat transfer is not just about temperature difference. Again, the students will write another Two-Minute Paper that cites specific evidence from their extensions to support this claim.
Resources
carsandwater. (2012, November 25). Red hot nickel ball in water (nice reaction) [Video]. https://www.youtube.com/watch?v=9qSEfcIfYbw
K20 Center. (n.d.). Gallery Walk / Carousel. Strategies. https://learn.k20center.ou.edu/strategy/d9908066f654727934df7bf4f505a54d
K20 Center. (n.d.). I Think / We Think. Strategies. https://learn.k20center.ou.edu/strategy/d9908066f654727934df7bf4f5065bfd
K20 Center. (n.d.). Two-Minute Paper. Strategies. https://learn.k20center.ou.edu/strategy/d9908066f654727934df7bf4f506cf73