P h a s e C h a n g e I n s t r uc ti o n a l C a s e : A s er i e s o f s t u de n t -c e nt er e d s c i e nc e l es s o ns
Lesson 1
Molecular Motion Shaker Box
Summary
Suggested Timeline
45 minutes
Materials
 3 CD cases per group
 2 different colored pony beads
 “Molecular Motion” probe
Prep
1. Set up each group with 3 CD
cases, 2 different colored pony
beads, and 1 copy of the
Molecular Motion probe.
2. The CD cases should represent 3
states of matter.
Objective(s)
 Students learn that matter exists in
moving particles and the freedom of
movement of these particles
depends upon the state of matter.
 An increase in temperature results
in a greater movement of the
particles.
Phase Change Instructional Case
Lesson 1
This lesson is an introduction to molecular motion within the three
different states of matter: solid, liquid and gas. The teacher will
elicit students’ prior knowledge on the subject by using a probe to
understand students’ misconceptions. Students will be
manipulating three conceptual models and then will continue to
manipulate and revise the model based on how temperature
affects particle motion. Lesson 0 on modeling can be a great way to
introduce students to the concept of modeling as a science and
engineering practice.
Teacher Background Knowledge
Atoms and molecules are in constant motion. In a solid, the
particles vibrate in place in fixed positions that maximize the
attraction between them. As the temperature of a solid increases
to a temperature that is just below its melting point, the molecules
vibrate faster in their fixed positions. In a liquid, the attractions
between molecules are still relatively strong (compared to the gas
state), but the position of individual molecules is no longer fixed.
Thus, liquids have the ability to flow and take the shape of their
container. In the gas state, molecules have enough energy to
move independently at high speeds undergoing frequent collisions.
In each of the three states of matter, as temperature increases, so
does the kinetic energy (motion) of the molecules. As you increase
the amount of shaking, you increase the amount of motion and
thus, increase temperature. The shaking of the container mimics
the addition of thermal energy and breaks the attraction between
the molecules.
The model has the advantage of showing how density is often
different. The teacher can address this concept and dispel the
misconception that it is the number of molecules that differentiate
solids, liquids and gases. You would expect there to be significantly
fewer particles in the same volume of gas than of a solid, for
instance, when discussing the concept of density. The advantage of
using pony beads is that you are seeing interactions and degrees of
freedom available to the particles in the different states of matter.
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Lesson 1
Molecular Motion Shaker Box
Standards 12
NGSS Performance Expectations:
This lesson supports students in progressing toward the NGSS Performance Expectation.
MS-PS 1-4: Develop a model that predicts and describes changes in particle motion, temperature, and
state of a pure substance when thermal energy is added or removed.
Emphasis is on qualitative molecular-level models of solids, liquids, and gases to show that adding or
removing thermal energy increases or decreases kinetic energy of the particles until a change of state
occurs. Examples of models could include drawings and diagrams. Examples of particles could include
molecules or inert atoms. Examples of pure substances could include water, carbon dioxide, and helium.
MS-PS 1-5: Develop and use a model to describe how the total number of atoms does not change in a
chemical reaction and thus mass is conserved.
Emphasis is on law of conservation of matter and on physical models or drawings, including digital forms
that represent atoms.
Assessment Boundaries: Assessment does not include the use of atomic masses, balancing symbolic equations,
or intermolecular forces.
In this lesson…
1
Science and Engineering Practices
Disciplinary Core Ideas
Cross Cutting Concepts
Developing and Using Models: Use
model of the CD cases and pony
beads to compare and evaluate
the three different states of
matter. Use the model to describe
the phenomena of phase
transition.
PS1.A: Structure and Properties of
Matter Gases and liquids are made
of molecules or inert atoms that are
moving about relative to each
other. In a liquid, the molecules are
constantly in contact with others; in
a gas, they are widely spaced
except when they happen to
collide. In a solid, atoms are closely
spaced and may vibrate in position
but do not change relative
locations. The changes of state that
occur with variations in
temperature or pressure can be
described and predicted using these
models of matter.
Cause and Effect Use the
model to predict phenomena
in the designed system of the
CD cases. Observe how
shaking and tilting the case
affects the pony beads. Listen
for observations.
Energy and Matter Matter is
conserved because atoms are
conserved in physical and
chemical processes. Note
that no pony beads were
gained or lost during the
entire activity.
NGSS Lead States. 2013. Next Generation Science Standards: For States, By States. Washington, D.C.: The
National Academies Press.
2
National Governors Association Center for Best Practices, Council of Chief State School Officers Title: Common
Core State Standards (insert specific content area if you are using only one) Publisher: National Governors
Association Center for Best Practices, Council of Chief State School Officers, Washington D.C. Copyright Date: 2010
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Lesson 1
Molecular Motion Shaker Box
In this lesson…
CCSS Mathematics
CCSS English-Language Arts
MP.2 Reason abstractly and quantitatively.
SL8.1C Pose questions that connect the ideas of
several speakers and respond to others’ questions
and comments with relevant evidence,
observations, and ideas.
8.F.B.5 Start preparing students to think about the
qualitative relationship between temperature, time
and phase transition.
Prior Knowledge
In grades 3-5, students have learned that because matter exists as particles that are too small to see, matter
is always conserved even if it seems to disappear.
Before this lesson, students must have been introduced to the idea that all matter is made up of particles
(atoms or molecules) that are so small we cannot see them directly. It is not necessary that students
understand the difference between atoms and molecules, only that matter is made up of small particles we
cannot see. If students are not familiar with this idea, briefly state that all matter is made up of small
particles we cannot see; water, for instance, is made up of individual particles of water called molecules.
Lesson
1. *Introduction to Modeling*: Have students understand the five important points in building conceptual
models. Students can differentiate between the model and the real thing, evaluating the model and its
limitations.
2. Probe: Start the lesson by giving the students the Molecular Motion Probe. This probe allows you to
gauge common misconceptions your students may have about molecular motion. (If necessary, briefly
explain that “molecule” is a term for a very small particle of matter we cannot see). After students have
responded silently to the probe in writing, ask students to go to one of four corners of the room based
on their response to the probe.
3. Ask students to explain to one other person in their corner their choice and then listen while their
partner explains their reasoning for the choice. Begin a class discussion about the reasoning for choosing
each of the four models.
Possible questions for whole-class discussion:
 “How does this model help explain what we observe when substances are heated?”

“Why is this model better than the others?”

“What kinds of things would we expect to observe if this is what particles actually do when
heated?”

“How could we test this model?”
4. Tell students that they will now investigate the effects of an increase in temperature on particles
(molecules) by using actual models of solid, liquid, and gas states of matter. Distribute the CD cases to
groups of 2-4 students.
5. Activity: Have students shake it, tilt it, and listen to each CD case. Have students first draw each case.
Underneath the drawings of each case, students write down their detailed observations, keeping in mind
what happens as they shake it, tilt it, and listen to it.
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Lesson 1
Molecular Motion Shaker Box
6. Questions to focus on:
 Which case best represents a solid, liquid, or gas? Why?

What happens to the overall pattern or arrangement of beads when the case is moved? How
might a higher temperature change this motion?

What can you do with the CD cases to show a higher temperature?

Which model from the probe (A, B, C, D) is most like the CD case model of particle motion?
Potential Pitfalls
The CD case models by themselves do not demonstrate that particles are always motion; latter activities in
the unit do demonstrate this key idea.