Energy Transfer in Temperature

Amounts Matter

High School


 Description 

Students use proportional relationships of temperature change rates and conduct an investigation to provide information about magnitude of properties and process.

Student investigations identify independent/dependent variables and controls, tools needed, measurements needed, and data required to support a claim that relates material amounts to thermal energy transfer.

Materials

Printed Material

  • 1 Student Handout: Amounts Matter (per student, group, or class)

Reusable

  • 3 Beaker, glass, 250 mL (per group)
  • 1 Hot plate (per group)
  • 1 Timing device (per group)
  • 1 Graduated cylinder, 100 mL (per group)
  • 1 Thermometer, probe (per group)
  • 1 Calculator, graphing (per group)
  • 1 Cable, link, for graphing calculator (per group)
  • 1 Computer, with software accompanying calculator (per group)
  • 1 Mitt, safety (per group)
  • 1 Tongs (per group)
  • 1 Goggles, safety (per student)

Consumable

  • Water, 350 mL (per group)
  • 1 Lab journal (per student)

Preparation

Student Handouts can be printed individually for student use, as a reusable class set, or assigned online. Review the Writing a Scientific Explanation Rubric Key for Teacher prior to conducting the CER with students.

Allow 350 mL of water, per group, to set out overnight. Gather materials and place them so students can easily access them. Choose a safe place for the students to place the hot glassware. If a sink is chosen, remind students NOT to turn on the water, or the hot glassware may break.

Temperature probes will be used in this sample investigation. A temperature probe, along with an interface and graphing calculator, is used to collect data. Temperature can be monitored or recorded at specific time intervals by using the probe manufacturers data-collecting program on the graphing calculator. The data is recorded into the calculator through the interface and graphing and can be downloaded onto a computer and used for reporting results in a laboratory report.

Set up the temperature probe, the interface, and the designated graphing calculators containing the appropriate programs for the measurement probes. Students must have a link cable to transfer the data to the computer. Be prepared to share the directions from the manufacturer which shows how to use the program and set up the parameters for the investigation.

If probes are not available, 12 thermometers may be substituted. Students should record the beginning temperature of the water and the temperature when it is boiling. Determine the best setting for the hotplates that will safely bring water to boil. Plan to review lab safety rules concerning handling normal and hot glassware and hot plates.

Visit Site  STEMcoach in Action

It looks like your students will be planning and implementing an investigation to determine proportional relationships of temperature change rates for different volumes of the same material. This scientific investigation will require a great deal of student independence. To learn more about scientific investigations as well as sustained inquiry, click on STEMcoach.

Facilitation

The following investigation is a sample investigation that is tightly aligned to the NGSS standards. Sample materials, procedures and anticipated student answers are provided. All investigations are inquiry-based, so, based on students’ comfort level, the teacher can guide them through differentiated, science-inquiry events.

A set of suggested procedures are given in the Student Handout. These procedures are to be used as an example. You may choose to guide the students in planning their own investigation by going through each of the suggested 10 steps before distributing the Student Handout, or have the students plan their investigations using the Student Handout as a guide.

Differentiation Points

The investigation is written to encourage the students to plan and implement their own investigation with your guidance. You can provide appropriate grouping/differentiated-inquiry with the following scaffolding suggestions:

Group students together who need more guided practice, and spend more time with them to develop their procedure. Let the other groups work more independently.

Group students with mixed needs, and have them work together to develop a procedure. Monitor all groups equally.

Pre-Investigation Discussion

  1. What have we discovered about thermal energy transfer so far?
  2. The type of material an object is made of affects thermal energy transfer. Some materials transfer energy more readily than others.
  3. Is thermal energy transfer always the same for objects of the same material?
  4. Accept all ideas.
  5. What would happen if two identical-sized blocks of ice were placed in direct sunlight?
  6. Both would heat up from the thermal energy transfer from the Sun and melt.
  7. Would they melt at the same rate?
  8. Yes.
  9. What would happen if one block is twice as big as the other?
  10. Accept all ideas.
  11. How could we test your ideas?
  12. Accept all ideas that are feasible for the classroom.
  13. When designing an investigation to determine if the amount of material affects thermal energy transfer, how much data will be needed to form a conclusion or to make a claim?
  14. A minimum of three different masses or volumes of a material will need to be tested to be able to establish a trend and support a conclusion or claim.

Tell the students their challenge is to plan and implement an investigation to determine if the amount of material (mass or the volume) that makes up a substance affects thermal energy transfer. Remind students to calculate the average change in temperature by dividing the total change in temperature by the total time tested.

Download

Student Handout: Amounts Matter

Post-Investigation Discussion

  1. Which volume of water reached 100°C in the least amount of time? In the greatest amount of time?
  2. Why is calculating the average temperature change over time an important step in this comparison?
  3. What statement could you make about the amount of thermal energy transfer in the two different volumes of water?
  4. In this investigation, water was used as the material. What do you predict will happen if three different volumes of sand were tested?

Post-Investigation Discussion Key

For future content reference, have students record their answers in complete sentences in their lab journals throughout the discussion.

  1. The 50 mL volume of water reached 100C in the least amount of time. The 200 mL volume of water reached 100C in the greatest amount of time.
  2. The beginning temperature of the different volumes of water were not the same, so just comparing the amount of time it took each volume to reach 100C is misleading. By using the average change in temperature over time, the amount of thermal energy required to increase the temperature of the different volumes can be compared.
  3. Less thermal energy transfer is needed to raise the temperature of a smaller volume of a material than a larger volume of the same material.
  4. I predict the results would be the same. The smaller volume of sand will heat more quickly (requiring less thermal energy transfer) than the larger volumes of sand. The largest volume would require the most thermal energy transfer in order to have the same change in temperature.

Conclusion and Scientific Explanation

In order for students to complete Step 10, students should write a conclusion and scientific explanation based on the following prompt: “What is the relationship between the amount of material in a substance and the thermal energy transfer?”

Sample Student Responses and Answer Key

Step 1: Does the amount of material in a substance affect thermal energy transfer?

Step 2: Thermal energy transfer is important when cooking, while trying to keep warm during the winter, and for maintaining ice and snow cover for sports like ice skating, skiing and snowboarding.

Step 3: The variables are the volume of room temperature water in a container (mL) and the time it takes to heat the water to 100 oC (minutes). The independent variable will be the volume of the room temperature water in a container. The dependent variable will be the time it takes to heat the water from room temperature to 100oC. The control will be the amount of heat applied to each beaker of water. The hot plate and water will be used in the same room to ensure consistent ambient temperature.

Step 4: This is an investigation where the variables are manipulated, so a hypothesis is needed. If the amount of a substance increases, the amount of energy needed to raise the temperature of that substance also increases resulting in more time needed to heat the substance.

Step 5: See Materials List.

Step 6: Care must be taken when using glassware. Students should not handle broken glass and must alert the teacher immediately if glassware is broken. Broken glass must be disposed of properly in a separate container. All lab safety procedures for handling hot glassware and working with hot plates must be followed. Safety splash goggles must be worn. Lab safety procedures for burns and scalds should be reviewed. All spills must be cleaned up immediately to avoid a slipping hazard.

Step 7: See enclosed Sample Procedures.

Step 8: Sample data collection is as follows:

Amount of Material and Thermal Energy Transfer Data
200 mL of water 100 mL of water 50 mL of water
Initial Temperature 21o C 25.5o C 28o C
Change in Temperature 79o C 74.5o C 72o C
Time to reach 100o C 14:42 minutes 12:14 minutes 1:51 minutes
Average change in temperature over time 5.4o/min 6.1o/min 38.9o/min

Step 9: Students should make a graph based on their data. Their graph should include a title, the independent variable on the x-axis, the dependent variable on the y-axis, labels that include units of measure, and the correct data collection represented as a line graph, which shows change over time, or a bar graph, which shows comparison. Have students write a general statement about their results from the graph. For example, students may say, Based on the line graph, I can conclude that the amount of material does affect the time it takes for thermal energy to transfer.“ Step 10: Student answers will vary based on their data, but students should note that the temperature took longer to rise in larger volumes of a substance.

Common Core Math Alignment

6th Grade Example

Based on the graph, have students determine the median change in temperature.

The median is the middle value of a numerically ordered set of data. (It does not matter if the data is in ascending or descending order.) For example, in the data set {4, 6, 6, 8, 11}, 6 is the median because it is in the middle of the numerically ordered data set.

Based on the graph, have students determine the mean change in temperature.

The mean is calculated by adding all the values in the data set and dividing the sum by the number of values in the data set.

Based on the graph, have students determine the range for the changes in temperature.

The range is calculated by subtracting the lowest temperature from the highest temperature.

Based on the graph, have students determine the mode in temperature change.

The mode is the value that appears most frequently in a data set.

7th Grade Example

Ask students determine which type of graph would best display the mean amount of time it took different volumes of water to reach 100 degrees. Have students justify their answers.

Answers will vary. Example: A bar graph is best to use because it shows comparisons.

8th Grade Example

Ask students determine which type of graph would best display the mean amount of time it took different volumes of water to reach 100 degrees. Have students justify their answers.

Answers will vary. Example: A bar graph is best to use because it shows comparisons.

CER Answer Key:

Sample claim

The amount or volume of material of an object has an effect on thermal energy transfer.

Sample evidence

  • 50 mL of water was heated to 100o C in 1:51 minutes.
  • 100 mL of water was heated to 100o C in 12:14 minutes.
  • 200 mL of water was heated to 100o C in 14:42 minutes.
  • Each volume of water began at different temperatures.
  • The 50 mL of water and a 72o C change in temperature.
  • The 100 mL of water and a 74.5o C change in temperature.
  • The 200 mL of water and a 79o C change in temperature.
  • The average change in temperature over time for the 50 mL volume was 38.9o/min.
  • The average change in temperature over time for the 100 mL volume was 6.1o/min.
  • The average change in temperature over time for the 200 mL volume was 5.4o/min.

Sample reasoning

The amount or volume of water had an effect on the amount of thermal energy transfer needed to raise the temperature of the room temperature water to 100o C. Each volume of water was raised from room temperature to 100o C using the same heat source. The smaller volume of 50 mL was raised to 100o C in less time (1:51 minutes) than the two larger volumes. The largest volume of 200 mL took the most time to reach 100o C (14:42 minutes). Since each volume of water had a different beginning temperature, the best way to compare the thermal energy transfer of the three is to compare the average change in temperature over time for each volume. The smallest volume (50 mL) of water had a much greater rate of change over time (38.9o/min) when compared to the rate for the largest volume (5.4o/min). This great difference indicates the volume of a material has a great effect on thermal energy transfer. The longer the water sat on the hot plate, the greater the amount of thermal energy transfer. Less thermal energy transfer is needed to raise the temperature of smaller amounts (mass or volume) of a material than the amount of thermal energy transfer needed to raise the temperature of larger amounts of the same material.

Download

Writing a Scientific Explanation Rubric Key

ELL Strategy

After completing the CER, have students trade, read another student’s CER, and ask questions to make sure they understand what was written. Then have students write a rebuttal or reflection based on the other student’s CER response.

Sentence Stems

Allow students to complete the following sentence stems before the discussion:

-My claim is ________.

-My evidence is ________ .

-My reasoning is ________.

-I heard you say ________, and I haven’t thought about that before. However, I think________.