administration student task rubric student work technical quality
Keep Cool
Contributed by: Council of Chief State School Officers (CCSSO/SCASS)


  1. Which container do you think will keep the water coldest for fifteen minutes? Why do you think so?
  2. Describe what happened to the water temperature in all three containers. Did the temperature change? If so, describe the change.
  3. Suppose you are going on a picnic and will be serving soft drinks in cups. What kind of cup would you use to keep the drinks cold? Explain why you would choose that kind of cup.

Item Description:

The exercise is intended to show the students the insulating quality of various types of containers. They are asked to test paper cups, styrofoam cups, and metal cans, to determine which type of container would be the best to use to keep drinks cool on a hot day.

One of each of the three types of containers is filled with ice water and a thermometer placed in each. Students are asked to record the temperature in each container after 30 seconds and after 15 minutes. The total difference in temperature for each type of container should then be determined and recorded.

Question 1 asks the students to hypothesize which container they think will keep the water the coldest and why (the exercise tells them to answer this question after they take the first reading but prior to the second). A good response will show the student understood the question and can explain why they chose one of the three types of containers. Since it is a hypothetical question there really are no wrong answers.

Question 2 and question 3 are to be answered after they finish the exercise. Question 2 asks the students to describe what happened to the water temperature in each of the three containers. If it changed they should describe the change. A good response will show the student measured and recorded their observations correctly to determine the total difference in temperature for each type of container.

Question 3 asks the students to choose which type of container or cup they would use on a picnic to keep drinks cold, and explain why they chose that kind of cup. A good response will show, if the exercise was done correctly, that the total difference in temperature was lowest for the styrofoam cup, and the students interpret this to mean it will keep drinks cool the longest.


Criterion 1:   (Question 1)  Student chooses one of the three types of containers, styrofoam, paper or metal, that they think will keep the water coldest,
    provides some type of explanation why they chose the container they did. The explanation does not need to be scientifically "correct." For example, the following are acceptable answers:

  1. Metal, because when I felt it without any water in it, it felt cold.
  2. Metal will keep it colder because when you put it in the refrigerator it will freeze.
  3. Styrofoam because it is thicker.

These are not acceptable responses:

  1. Styrofoam because it's styrofoam.
  2. Fiberglass works well in our attic.
Criterion 2:   (Question 2)  Student describes if the temperature changed or remained the same in any of the three containers. For example:

  1. The water is warmer at 15 minutes than at 30 seconds in all the cups.
  2. After 15 minutes the water in the styrofoam cup is the coolest.
  3. The total difference in temperature was the same for all three cups.
  4. The temperature changed by 4 degrees.

Note: In D, the specific type of container is not stated. The criterion is met if the student notes and observes if the temperature became warmer or cooler.

Criterion 3:   (Question 3)  Student states that a styrofoam cup would be best to keep the drinks cold. Paper or metal cups are acceptable answers if it is clear that the student gave this response based on the results of their experiment - total difference in temperature.
Criterion 4:   In question 3, the student responds that styrofoam will be best to keep drinks cold,
in any of the three questions, the student explains why styrofoam will work the best.
The explanation must be based on the exercise or on how styrofoam works as an insulator. For example:

  1. Styrofoam because the total difference in temperature is lowest.
  2. Styrofoam because it is an insulator and it traps the cold inside (or keeps the heat out).

The following are not acceptable response:

  1. Styrofoam because my mom always brings styrofoam cups when we go on a picnic.
  2. Styrofoam because it is the thickest.


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