Phase Change 2.2

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Phase Change
Lesson 2.2: Understanding
Energy Transfers

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Activity 1
Warm-Up

5 MIN

Phase Change: Lesson 2.2

Open Ended

A student chemist created the following model to explain a phase change they observed at home: A chocolate bar was placed in a hot pan. The chocolate began to flow, and it took the shape of the pan.

Explain the changes you would make to the model in order to correctly show what changed the chocolate molecules’ freedom of movement.

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Activity 2
Experimenting with
Magnetic Marbles

10 MIN

Phase Change: Lesson 2.2

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Key Concept

Activity 2

Phase Change: Lesson 2.2

6. When energy is transferred to or from a
substance, it can change the molecules’
freedom of movement.

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Today, we’ll look deeply at what happens to
molecules when energy is added or removed.

Activity 2

Phase Change: Lesson 2.2

Investigation Question:
Why can transferring energy into or out of a substance
change molecules’ freedom of movement?

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Activity 2

Phase Change: Lesson 2.2

Claim 1: Transferring energy into
or out of a substance changes its
temperature, which changes the
molecules’ freedom of movement.

Claim 2: Transferring energy into
or out of a substance changes the
molecules’ kinetic energy, which
changes their freedom of
movement.

Claim 3: Transferring energy into
or out of a substance changes the
molecules’ speed, which changes
their freedom of movement.

Here are three claims
that could answer the
Investigation
Question.

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Activity 2

Phase Change: Lesson 2.2

First, we’ll gather
evidence about the
claims by using a model
in which magnetic
marbles represent
molecules.

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Follow instructions.

Don’t taste things.

Smell substances like a chemist.

Protect your eyes.

Protect your hands.

Keep your hands away from your face.

Tell your teacher if you have allergies.

Be calm and careful.

Report all spills, accidents, and injuries to your teacher.

Avoid anything that could cause a burn.

Wash your hands after class.

Safety Guidelines for Science Investigations

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Investigation Notebook pg 1

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1.Container lids should remain closed when shaking the marbles.

2.Keep tablets and computers out of the way when completing this
activity. This will prevent devices from being knocked to the floor. It
also prevents digital devices from being damaged by the marbles’
magnetic fields.

3.Do not put the marbles near or in your mouth. Ingesting marbles could
be dangerous to your health.

Magnet Safety Guidelines

Activity 2

Phase Change: Lesson 2.2

Open Ended

How could you add energy to the marbles?

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1. Observe the Marbles

2. Add a Little Energy

3. Vary the Amount of Energy

Place the container of
marbles on the table.
Observe the marbles.
(Remember that the marbles
represent molecules.)

Magnetic Marbles Activity

Activity 2

Phase Change: Lesson 2.2

Add a small amount of energy
by shaking the closed
container gently. Observe
the marbles. Consider the
effect adding energy to a
substance has on the
molecules.

Experiment by adding
different amounts of
energy to the container
(or by letting the container
rest). Observe what happens
to the marbles.

Open Ended

1. Place the container of marbles on the table. Observe the marbles. Remember the marbles represent molecules.)

2. Add a small amount of energy to the marbles by shaking the closed container gently. Observe the marbles. Consider the effect adding energy to a substance has on the molecules.

3. Experiment by adding different amounts of energy to the container (or by letting the container rest). Observe what happens to the marbles.

4. Describe how transferring energy into the container affected the speed of the marbles.

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Activity 3
Using the Sim to Observe
Energy Transfer

20 MIN

Phase Change: Lesson 2.2

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Activity 3

Phase Change: Lesson 2.2

Next, we’ll look at what
happens to molecules in
the Sim when energy is
added to or removed
from a substance.

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Activity 3

Phase Change: Lesson 2.2

When working in the
Sim, you’ll need to pay
close attention to the
kinetic energy of the
molecules.

You’ll need to turn on
View Kinetic Energy.

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Activity 3

Phase Change: Lesson 2.2

When you show kinetic energy, the molecules
will become different shades of yellow.

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Activity 3

Phase Change: Lesson 2.2

You will also use the
Transfer Energy In and
Transfer Energy Out
buttons and observe how
this affects the kinetic
energy of the molecules.

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Activity 3

Phase Change: Lesson 2.2

Claim 1: Transferring energy into
or out of a substance changes its
temperature, which changes the
molecules’ freedom of movement.

Claim 2: Transferring energy into
or out of a substance changes the
molecules’ kinetic energy, which
changes their freedom of
movement.

Claim 3: Transferring energy into
or out of a substance changes the
molecules’ speed, which changes
their freedom of movement.

Did your observations
from the Sim and the
hands-on activity
support or refute any
of these claims?

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Activity 4
Explaining Zooming in on
Phase Change

10 MIN

Phase Change: Lesson 2.2

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Activity 4

Phase Change: Lesson 2.2

Claim 1: Transferring energy into
or out of a substance changes its
temperature, which changes the
molecules’ freedom of movement.

Claim 2: Transferring energy into
or out of a substance changes the
molecules’ kinetic energy, which
changes their freedom of
movement.

Claim 3: Transferring energy into
or out of a substance changes the
molecules’ speed, which changes
their freedom of movement.

Remember to refer to
these claims as you
watch the video.

You should look for
evidence to support or
refute these claims.

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Open Ended

Based on the evidence from the Sim, the hands-on activity, and the video, which claims do you think are best supported?

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Vocabulary

Phase Change: Lesson 2.2

the energy that an object has because it is moving

kinetic energy

Activity 4 - Screen 1

Open Ended

How can we tell how fast molecules are moving if we can’t see the molecules?

Open Ended

Describe how transferring energy into the substance affected the speed of the molecules.

Open Ended

As the speed changed, what did you notice about the molecules’ freedom of movement?

Open Ended

Did your observations provide evidence to support any of the claims?

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Phase Change: Lesson 2.2

Temperature is a
measure of how hot or
cold something is.

The higher the
temperature is, the
more energy it has.

Activity 4 - Screen 1

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Key Concept

Phase Change: Lesson 2.2

7. Temperature is a measure of the average
kinetic energy of the molecules of a
substance.

Activity 4 - Screen 1

Open Ended

Why can transferring energy into or out of a substance change molecules’ freedom of movement?

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Let’s work together to create a claim that
answers the Investigation Question.

Phase Change: Lesson 2.2

Investigation Question:
Why can transferring energy into or out of a substance
change molecules’ freedom of movement?

Activity 4 - Screen 2

Dropdown

When you transfer energy into a substance, the temperature​ ​

Select answer

Dropdown

When you transfer energy into a substance, the molecules’ kinetic energy​​

Select answer

Dropdown

When the kinetic energy of molecules​

Select answer

the molecules are moving​

Select answer

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Phase Change: Lesson 2.2

Key Concept

8. Transferring energy to a substance
increases the kinetic energy of that
substance’s molecules. Transferring energy
from a substance decreases the kinetic
energy of that substance’s molecules.

Activity 4 - Screen 2

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End of Lesson

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Phase Change: Lesson 2.2