Energy Learning Community

Lesson 4 - How Can Ice Have Heat?

Lesson Plan

Grade Level:

6th Grade

State Standards:

Physical Sciences (Chemistry and Physics) Grades 6-8
14. Recognize that heat is a form of energy and that temperature change results from adding or taking away heat from a system.
16. Give examples of how heat moves in predictable ways, moving from warmer objects to cooler ones until they reach equilibrium.

Essential Question:

How is energy conserved in a chemical or a physical process?

How can you determine the amount of energy absorbed or released in a chemical or physical process?

Lesson Question:

What is heat and how can we determine its movement?

Introduction:

Science tells us that there is heat in ice, but when I touch ice, it feels cold. How can there be heat in something that feels cold? It seems counter-intuitive until we dig into what heat really is and how it can be measured. In the following investigations, we will distinguish differences between the sensations of hot/cold and what heat actually is. We'll explore the tool used to measure heat and demonstrate how the direction of heat flow is predictable.

Task:

Using some demonstrations, simulations, videos, and lab investigations, you will develop a science understanding of heat as a form of energy and examine what determines the direction of heat flow. Your task will be to apply your understanding by creating a presentation that will convince other viewers that Ice does have Heat.

Lesson Experiences:

Elicit (Prior Knowledge):
Warm-Up Activator Question--

Answer these questions:
“What do you think will happen if water is added to a glass of ice cubes?”
Write your response in your Science journal then, discuss the possibilities with your table mate. You will share your responses with the class.
Note: Class responses may reveal a range of answers –‘water will get colder’, ‘ice will melt’, ‘temperature will change’, ‘water will freeze’, ‘outside of glass will get wet’, etc. Write the responses on the board to refer to during the lesson.

How can we determine what change would happen? Is there something we can measure in this example that will help us know?

Engage:
Let’s try to measure the temperature of two objects and see if we can find a difference.

Activity 1: “Stone and Wood”
Step 1. On your tables are two samples. One is polished stone and one is smooth-sanded wood. Touch each one with your hand or place it next to your cheek to feel their temperature.
Step 2. Which material felt colder?
Which material felt warmer?
Step 3. Use the infrared thermometer to measure the temperature of both samples and record their temperatures:
Temperature of Stone: C Temperature of Wood: C
Step 4. Did the thermometer confirm your findings in Step 2? Describe:

Most of you found the stone to feel colder than the wood, but the thermometer found that they were both a similar temperature. How can our bodies give us such a different result? We are going to discuss this but first, let’s explore some more about heat.

Activity 2: "Changes in State"
In your Warm-Up responses, you identified several possibilities- temperature change, ice melt, water freeze. These changes involve heat and the movement of heat from one source to another. We know that water can exist in different states (Solid, liquid, and gas). What happens to cause water to freeze, or to melt or to evaporate?

Investigate this question with the following simulation:

PhET Simulation "States of Matter"

States of Matter: Basics
Click to Run



Step 1. In right hand column under “Atoms and Molecules”, select “WATER”.
Step 2. In the drawing, find the thermometer reading 157K and observe how the molecules are all connected and vibrating. This represents water in a SOLID state.
Step 3. Back to the right hand column, under “Change State”, select LIQUID.
Step 4. What changes did you observe? What is the thermometer reading?
Step 5. Again, under “Change State”, select GAS.
Step 6. What changes did you observe? What is the thermometer reading?
Step 7. Go to the gray bucket under the yellow cylinder and adjust the slide up and down to see how adding or removing heat affects the physical state of water.
Step 8. Make adjustments to simulate these changes and record the results:

Gas state + heat =
Gas state – heat = or
Liquid state + heat =
Liquid state – heat =
Solid state + heat = or
Solid state – heat =

Conclusion:
Based on your changes and the results in the simulation, what must happen in order for water to change from one physical state to another? Explain your answer.

Before we go any farther, let’s do a little explaining to make sure we are all understanding heat.

Explain
In Activity 1 we felt two samples that we thought were hot and cold materials. But we found out that they were both similar temperatures. This tells us that our bodies are not good thermometers. That’s because our bodies have heat too.

So, when we experience something hot, we mean that it is hotter than our bodies are, and when we experience something cold it is colder than our bodies. This is measuring a relative difference in temperature, the difference between our body temp and the sample temp. (Note: The reason the two samples 'feel' like different temperatures has to do with the way that heat is transferred (Conduction) and we'll cover this is a separate lesson.)

“Heat” is something different that Hot and Cold. Heat is energy and heat has a quantity that can be measured. When energy is added to water, the water molecules respond by moving faster and colliding with each other with greater frequency. Water with less energy will have molecules that move at a slower speed with fewer collisions.

Temperature is a measurement that indicates the average amount of energy of motion of the molecules in that substance. So, when you put a thermometer in a glass of boiling water, the water molecules collide with the molecules in the glass tube of the thermometer, which then collide with the molecules of the alcohol in the tube causing them to move faster and collide more. This increased speed and molecule movement causes the alcohol to consume greater volume, so the alcohol rises up the glass tube. The position of the alcohol in the tube corresponds to the amount of energy of the molecules moving in the substance. Confused??

Check out this Bill Nye video for clarification. While you watch it, listen and write the definitions for the following terms:
Heat
Thermal energy
Temperature
Three methods of Heat Transfer

Bill Nye the Science Guy on Heat



Describe the role that molecules have in heat and heat transfer.
Explain in your own words how a thermometer registers a temperature.

Record these definitions and descriptions on flashcards using the link below to Quizlet.

http://quizlet.com/create-set




This second simulation is helpful to demonstrate the flow of heat from an energy source into a material and the different rates with which these materials change temperature both increasing and decreasing over time.

PhEt Simulation "Energy Forms and Changes"

Energy Forms and Changes
Click to Run



Open the simulation and check the box in the upper right corner to show energy symbols “E”. Begin by clicking and dragging one of the objects (Iron, Brick, or Water) up onto the stand. Then, click and slide on the control bar under the stand to either add heat or remove heat. The “E” represents energy and indicates the direction that energy is moving in the process.

After trials with each material, click on the thermometers in the top left and drag them into each of the materials. In your Science Journals record the amount of time that is required for each material to reach its maximum temperature and record the time required for each material to cool down to room temperature. What do these times indicate about the molecule activity in each material?
Why does the water stop getting hotter at some point and the brick and iron continue to get hotter?


Elaborate:

Activity 3: "Heat Directions"
With your understanding of heat and heat flow, you now have a chance to put this to work. In this Stations Activity you will be investigating the heat flow between systems of different temperatures. The procedure is the same for each station, but the temperatures of the test tubes and water baths will be different. Make your prediction at each station before beginning the investigation.


Steps for each station:
1. Write your prediction which direction the heat will flow for this station (from tube to bath, or from bath to tube)
2. Add the water temperature indicated to the water bath, see below.
3. Add the water temperature indicated to the test tube, see below.
4. Place thermometers into the water bath and the test tube.
5. Place the test tube into the water bath.
6. For a duration of 5 minutes, record temperature readings every 20 seconds for both thermometers in your Data Table.
7. Empty your test tube and water bath for the next group.
8. Interpret your data to determine what changes are happening to the test tube water and/or the water bath water.
9. Draw a diagram of the setup and label the start and end temperatures for both the test tube and the water bath. Draw arrows to indicate any direction that heat may be moving from a source to new location.

Station 1:
Water Bath Temperature 20 degrees C
Test Tube Water Temperature 90 degrees C

Station 2:
Water Bath Temperature 20 degrees C
Test Tube Water Temperature 50 degrees C

Station 3:
Water Bath Temperature 90 degrees C
Test Tube Water Temperature 20 degrees C

Station 4:
Water Bath Temperature 5 degrees C
Test Tube Water Temperature 90 degrees C


Extend:
Think of other situations where heat is involved and try to identify the source and direction of heat flow. How is your house heated in the winter? How does your body lose heat in the summer? What is the heat source for warm summer days and what changes to cause cold winter days?

 

Conclusion:

After these classes investigating the nature of heat, how it is accurately measured, and how it moves, you should be able to :

Define and describe "HEAT" and differentiate heat from the relative descriptions of "hot" and "cold."

Explain that temperature change results from adding or taking away heat from a system.

Provide accurate examples of heat movement and indicate the predictable direction of the movement from substances with greater molecular movement to substances with less molecular movement until these substances reach equilibrium.

Assessments:

Show us what you know. Prepare an electronic presentation (choose an application below) that includes what you have learned about heat to convince a viewer that there is Heat in Ice. Your presentation must include the following:

  1. Define each term: Heat, Thermal Energy, Temperature.
  2. Describe the response of water molecules to increased energy.
  3. Describe how a thermometer works and how this is a measure of thermal energy.
  4. Explain how the amount of heat in an ice cube can be measured.
  5. A discussion that convincingly explains how there is heat in ice.
  6. Illustrate the direction of heat movement between an ice cube and the water around it in a glass.
  7. Provide graphic images, video clips, simulations, or animations to support you description.

Presentation applications:
http://www.flickr.com/creativecommons/
http://commons.wikimedia.org/wiki/Main_Page
http://images.google.com/
http://edu.glogster.com/
http://prezi.com/

You will be able to....

Exemplary

Intermediate

Novice

Inadequate

%

Define the three terms
and provide examples

All 3 definitions
are correct with
related examples

2 definitionsare correct with
related examples

Some definitionsare incorrect with
examples are not
related

All definitionsare incorrect and
no examples are
provided

20%

Describe response of
molecules to adding
or removing heat

Description is
thorough and
accurate

Description is
accurate

Description is
inaccurate

No description
is provided

20%

Describe how a
thermometer works
and measures
thermal energy

Description isthorough and
accurate with
sequence of heat
flow provided

Description is accurate, but
omits heat flow
sequence

Description isinaccurate

No descriptionis provided

15%

Explain heat
measurement of
ice cube

Explanation is
complete and
accurate

Explanation
describes
instrument
but omits role of
molecular
movement

Explanation is
inaccurate

No explanationis provided

15%

Convince viewer of
heat in ice

Logic and sequence
is convincing

Logic is convincing
but sequence is not

Neither logic nor
sequence is
convincing

No attempt is
made is convince
viewer

15%

Correctly diagram
heat flow example

Diagram is correct

Diagram is correct

Diagram is incorrect

No Diagram is
provided

15%

Resources:

7 E Learning Cycle- "Expanding the 5E Model" by Arthur Eisenkraft, from "The Science Teacher", Vol. 70, no. 6, 2003, National Science Teachers Association
PhET Simulation "States of Matter"- http://phet.colorado.edu/en/simulation/states-of-matter
Flash Cards application- http://quizlet.com/
Bill Nye YouTube Video "Heat"- http://www.youtube.com/watch?v=Iv97uC7ZjBk
PhEt Simulation "Energy Forms and Changes" - http://phet.colorado.edu/en/simulation/energy-forms-and-changes
Applications for presentations:
http://www.flickr.com/creativecommons/
http://commons.wikimedia.org/wiki/Main_Page
http://images.google.com/
http://edu.glogster.com/

Teacher Notes:

Image Credits:

Ice cubes melting in glass

By Mysid (Own work) [Public domain], via Wikimedia Commons

http://commons.wikimedia.org/wiki/File%3AMelting_icecubes.gif

Thermometer

Nino Barbieri, 2007, via Wikimedia Commons

http://commons.wikimedia.org/wiki/File:-_Thermometer_-.jpg