Investigation Sequence

Title

Heat and Temperature

Written by:

autho                 Date

 

Focus Questions

 

Concepts

Content: Earth, Physical, & Life

Heat is transferred from a source to a receiver.
Heat is transferred in predictable ways, flowing from warmer objects to cooler ones, until both reach the same temperature.
Hot and cold objects will transfer heat energy until they reach equilibrium.
Heat is a measure of the amount of internal energy that an object receives or gives off.
Temperature is a measurement of the expansion of materials given different amounts of heat.
Heat can be measured by its effect on the amount of ice it can melt.
Temperature is a measure of how hot a substance is.
The amount of water at a specific temperature is related to the amount of internal heat energy present.
The heat energy possessed by an object is related to the quantity of matter present and its temperature.

Cross cutting concepts

 

Science Practice

Observations are used to help make explanations.
Recording observations helps remember specific information.
People learn by observing interactions with objects.
Properties of matter can be measured using thermometers.
Observations are made when someone conducts an experiment.
Temperature is measured with a thermometer.

Personal, Social, Technology, Nature of Science, History

 

Background information

Misconceptions

Heat and temperature are the same thing.
More heat means higher temperature, and/or more cold means colder temperature.
Temperature is a measure of heat.
Hot water is more powerful and it will greatly change the substance that it is added to, no matter the volume of each.
A thermometer measures heat.

Diagnostic
When asked, the students will understand that the temperature of the water with which you started and the amount off water with which you started are of equal importance.

Formative
The students will discuss what happens when two equal amounts of water with two different temperatures (one should be 0 degrees Celsius and the other should be about 30 degrees Celsius) are mixed together. Then, the students will predict what happens when you mix unequal amounts of water that have different temperatures.

Summative
The students will be able to decide how long it will take to cool or heat things and they should be able to decide how much cold water they need to mix into hotter water to make it a certain temperature.

Generative
The students will explain what they conclude about mixing two equal amounts of water that have different temperatures.  I will also ask them what they conclude about mixing a very small amount of water at one temperature with a lot of water at another temperature.

Diagnostic
The students will observe what happens when they mix two different glasses of water and then record their observations.

Formative
The students will observe what happens when two equal amounts of water with two different temperatures (one should be 0 degrees Celsius and the other should be about 30 degrees Celsius) are  mixed together.  Then, the students will observe what happens when you mix unequal amounts of water that have different temperatures.

Summative
The students will observe how long it will take to cool or heat things and how much cold water they need to mix into hotter water to make it a certain temperature.

Generative
The students will measure the temperatures of the mixtures with a thermometer.

Materials: Per group of four:  Twenty one Styrofoam cups, hot water, cold water with ice cubes, crushed ice, thermometer, paper towels, paper, measuring cup.

Objective: The students will solve everyday problems about heat and temperature in materials. They will make predictions of the resulting mixture of hot and cold water along with observations of the results.  They will determine that the heat energy  possessed by an object is related to the quantity of matter present and its temperature. 

Rationale: People need to understand that when mixing water, the temperature and the amount of the water involved are both important.  This is because single molecules may have a large amount of heat energy, but if there are not a lot of molecules, there will not be a lot of heat in the entire sample.

Activity Sequence

v    Exploration Procedure

The students will get into groups of four.

I will ask them what happens when two equal amounts of water with two different temperatures (one should be 0 degrees Celsius and the other should be about 30 degrees Celsius) are mixed together.

Let the students feel the water in both cups, then have them make predictions.

Then, have the groups measure the water temperatures, mix them together, measure the result, and record the observations.

The groups will be required to get two Styrofoam cups, hot water, cold water, a thermometer, paper, and a measuring cup.

After the students record their observations, the students will discuss the results as a group.  The students will find that mixing equal quantities of water at different temperatures produces a temperature midway between the two.

Then, the students will fill two Styrofoam cups with different amounts of water that have different temperatures (the small amount should be 45 degrees Celsius and the larger amount should be 0 degrees Celsius).

The cups should then be added together. Then the students should measure the result, and record their observations. Mixing these together produces little change in the temperature of the cold water.

The student will discuss the results of this activity and describe what happened to the water temperature in their groups.

                        Invention Procedure

The students will report their results of the exploration activities to the whole class.

I will have the students to compare the results of all of the groups.

Then, I will ask the students to explain what they conclude about mixing two equal amounts of water that have different temperatures.

I will also ask them what they conclude about mixing a very small amount of water at one temperature with a lot of water at another temperature.

Finally, I will ask them what is more important, the temperature of the water with which you started or the amount of water with which you started.

While we are discussing these things, I will also explain that the temperature and the amount of the water involved are both important.  This is because single molecules may have a large amount of heat energy, but if there are not a lot of molecules, there will not be a lot of heat in the entire sample.

Then the students, in their groups of four, will place one-fourth cup of crushed ice in five drinking cups.

Then, the students will measure out four different amounts of hot water (three-fourths cup, one-half cup, one-fourth cup, and one teaspoon) into other cups.

The students will dump each glass of hot water into a glass with ice.

Ask the student to make observations.

After five minutes have passed, the students notice how much ice is left in each cup.  Have them relate the amount of ice left to the amount of hot water added to the cup.  Have them record their observations. 

In class discussion, ask the students to explain why different amounts of ice were found in each cup.

I will explain that the added water was all at the same temperature.  Only the amount of water varied. If more hot water was added to the ice, it is the same thing as adding more heat.

Then, I will explain that heat and temperature are two different properties of materials.  Temperature is measured with a thermometer and it indicates the quickness of motion of speed energy each particle of water has.  Heat energy is a measure of how much energy all the particles in an object have lost or gained.  It shows the total amount of internal energy transferred to or from a specific amount of water.

Discovery Activity

The students will remain in their groups of four.

Give the students the following problem: Mary is having a cup of coffee.  She pours herself an almost-full cup of coffee.  The temperature of the coffee is about 50 degrees Celsius.  She adds a table spoon of cold milk to the coffee.  What temperature is her coffee now?  Write and explain your prediction on a piece of paper.

Ask them to explain a procedure to collect evidence that would support their answer.
Get one almost full cup of water, a second cup one-fourth full of cold water, and one tablespoon.
Measure and record the temperature of both cups of water.
Next, they should pour one tablespoon of cold water into the hot water cup.
Then measure and record the temperature of the mixed cup of water and compare it to their prediction. 
Find that the temperature should still be around 45 degrees Celsius.

Next, ask the students to solve the following problem by using hot water, cups, and a thermometer:
Jim is having hot soup for dinner, but it is too hot to eat. It is about 50 degrees Celsius.  He does not want to wait to eat it, so about how much cold water should he add to it.  There is about one cup of soup in the bowl, so how much cold water should he add to his soup to make it 40 degrees Celsius? 
Before doing the experiment, the students should make a prediction and explain it.

Next, discuss the results.

See if they can explain that by mixing different amounts of water and by melting ice with different amounts of water, they should be able to apply their knowledge of heat and temperature to their daily live. They should know how long it will take to cool or heat things and they should be able to guess how much cold water they need to mix into hotter water to make it a certain temperature.

Activity Descriptions

 

Dr. Robert Sweetland's notes