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Mixtures and Solutions: Particle Theory of Matter
Science Resource Package: Grade 7
Mixtures and Solutions:
Particle Theory of Matter
New Brunswick Department of Education
September 2009
Acknowledgements
The Department of Education of New Brunswick gratefully acknowledges the contributions of the
following groups and individuals toward the development of the New Brunswick Science
Resource Package for Grade 7 Mixtures and Solutions: Particle Theory of Matter:
 The Science Resource Package Development Team:
•
•
Chris Piers, School District 18
Grant Williams, School District 18
 Science East:
•
•
Michael Edwards, Director of Programming
Karen Matheson, Director of Education
 Kathy Hildebrand, Learning Specialist, Science and Mathematics, NB Department of Education
 Science Learning Specialists and science teachers of New Brunswick who provided invaluable input
and feedback throughout the development and implementation of this document.
Note that at the time of posting, all URLs in this document link to the desired science
content. If you observe that changes have been made to site content, please contact
Kathy Hildebrand katherine.hildebrand@gnb.ca, Science Learning Specialist, at the
Department of Education.
2009
Department of Education
Educational Programs and Services
TABLE OF CONTENTS
RATIONALE ........................................................................................................................................................ 1
BACKGROUND INFORMATION ....................................................................................................................... 3
PRIOR KNOWLEDGE: .................................................................................................................................................3
COMMON MISCONCEPTIONS:....................................................................................................................................3
DID YOU KNOW ? .......................................................................................................................................................3
INSTRUCTIONAL PLAN .................................................................................................................................... 5
ACCESS PRIOR KNOWLEDGE ...................................................................................................................................5
1ST CYCLE ..................................................................................................................................................................6
Separating Mixtures Activity .............................................................................................................................7
Reflection: Class Discussion ............................................................................................................................9
Reflection: Individual ........................................................................................................................................10
Think like a scientist .........................................................................................................................................10
2ND CYCLE ...............................................................................................................................................................11
Heterogeneous or Homogeneous Activity ....................................................................................................11
Reflection: Class discussion ...........................................................................................................................14
RD
3 CYCLE...............................................................................................................................................................15
Activity – Smaller than the eye can see ........................................................................................................15
Activity – Matter’s Particles .............................................................................................................................16
Reflection: Class discussion ...........................................................................................................................16
Reflection: Journal ...........................................................................................................................................17
SUPPORTING CLASS DISCUSSION ............................................................................................................. 19
MATERIALS LIST ............................................................................................................................................. 21
STUDENT VERSION OF OUTCOMES ........................................................................................................... 22
SEPARATING MIXTURES ............................................................................................................................... 23
HETEROGENEOUS OR HOMOGENEOUS ACTIVITIES ............................................................................. 24
MATERIALS: ..................................................................................................................................................... 24
OBSERVATION CHART SHEET .................................................................................................................... 25
CHECKLIST SHEET ......................................................................................................................................... 26
OBSERVATION CHECKLIST .......................................................................................................................... 27
STUDENT RECORD ......................................................................................................................................... 28
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Mixtures and Solutions: Particle Theory of Matter
Rationale
This resource package models current research in effective science instruction and
provides an instructional plan for one topic selected from the Grade 7 Atlantic Canada
Science Curriculum. This curriculum includes STSE (Science, Technology, Society and
Environment) outcomes, Skills outcomes, and Knowledge outcomes – all of which are
important for building a deep understanding of science and its place in our world.
As has been true of our ancestors, we all develop “explanations” about what we observe
which may or may not be valid. Once ideas are established, they are remarkably
tenacious and an alternate explanation rarely causes a shift in thinking. To address
these misconceptions or alternate conceptions, students must be challenged with
carefully selected experiences and discussion.
A key part of this instructional plan is accessing prior knowledge. It is recorded in a
way that it can and will be revisited throughout the topic. The intent is to revise, extend,
and/or replace students’ initial ideas with evidence-based knowledge.
Science is not a static body of facts. The process of exploring, revising, extending, and
sometimes replacing ideas is central to the nature of science. Think of science as an
ongoing evidence-based discussion that began before our time and that will continue
after it. Science is often collaborative, and discussion plays a key role. Students’
learning of science should reflect this as much as possible.
The intent of this instructional plan is to encourage a constructivist approach to
learning. Students explore an activity, then share, discuss and reflect. The telling of
content by the teacher tends to come after, as an extension of the investigation (or
experience) explored by the students.
The learning is organized into cycles. The partial conceptions and misconceptions are
revisited in each cycle so that students’ ideas will be revised. Each cycle will result in
deeper and/or extended learning.
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Mixtures and Solutions: Particle Theory of Matter
Hands-on activities are part of the instructional plan. Inquiry activities tend to be most
structured in the first cycle. The teacher provides the question to investigate and gives a
procedure to follow. In subsequent cycles, less structure tends to be given. For
example, students may be given a question and asked to develop an experimental plan
which they then implement. The goal is to move towards open inquiry in which
students generate a testable question, develop an experimental plan using available
materials, implement the plan, record relevant observations, and make reasonable
conclusions. The included activities are meant to start this journey.
Discussion and written reflections are key parts of the lessons. Discussion (both oral
and written) is a vehicle that moves science forward. For example, when scientists
publish their evidence and conclusions, other scientists may try to replicate results or
investigate the range of conditions for which the conclusion applies. If new evidence
contradicts the previous conclusions, adjustments will be required. Similarly, in this
instructional plan students first do, then talk, then write about the concept. A section on
supporting discussion is included in this resource package.
Assessment tasks are also included in the instructional plan and assess three types of
science curricular outcomes: STSE, Skills, and Knowledge. These tasks are meant to
be used as tools for letting the teacher and the students know where they are in their
learning and what the next steps might be. For example: Has the outcome been met or
is more learning required? Should more practice be provided? Is a different activity
needed?
When assessment indicates that outcomes have been met, it will provide evidence of
achievement. This evidence may be sufficient and further formal testing (paper-pencil
tests) may not be required to demonstrate that outcomes have been met.
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Mixtures and Solutions: Particle Theory of Matter
Background Information
Prior Knowledge:
In grade five students studied a unit on properties and changes in materials. They would
have experience:
 observing and describing physical properties of materials
 describing properties of solids, liquids, and gases
 identifying and describing physical changes
 identifying and describing chemical changes
Common Misconceptions:
Student ideas concerning matter being made of small particles will be unclear.
Individuals may have very different misconceptions about small bits.
There could be some confusion between the smallest unit of life, the cell, and the
smallest unit of matter, the atom.
When thinking about the word “mixtures”, students may only think about chemistry and
mixing chemicals as opposed to things they may use and see every day.
Students may think that a material is called a “mixture” when the different parts are
evident to the eye. In fact, some heterogeneous mixtures may appear as if they are
“solutions” (e.g. milk, orange juice...)
Did You Know?
Properties: characteristics or attributes used to describe matter (such as colour, odour,
and density)
Mixture: made up of two or more different types of materials
Mixtures can be heterogeneous: made up of parts that retain their own properties.
Taking multiple samples from different locations within a heterogeneous mixture will
result in non-identical samples.
Mixtures can be homogeneous – are the same throughout and the different parts are
combined in a way that there is one set of properties. Taking multiple samples from
different locations within a homogeneous mixture will result in identical samples.
Homogeneous mixtures are called solutions.
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Mixtures and Solutions: Particle Theory of Matter
Pure substances: are composed of only one type of particle
matter
mixtures
heterogeneous
pure substances
homogeneous
e.g. sugar
calcium carbonate
water
Particle Theory
The particle theory of matter says that all matter consists of many, very small particles
which are in a constant state of motion. The particles might be molecules, atoms or ions.
The behaviour and properties of materials can be explained by using a particle model
which helps us visualize what is happening on a very small scale. Models help us
understand, but should also be recognized to have limitations.
Solids
Liquids
Gases
The particles are held
close together
The particles are fairly
close together with some
attraction between them
The particles have little
attraction between them
The particles are in fixed
positions but they do
vibrate
The particles are able to
move around in all
directions but movement is
limited by attractions
between particles
The particles are free to
move in all directions and
collide with each other and
with the walls of a container
and are widely spaced out
New Brunswick Science Resource Package: Grade 7
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Mixtures and Solutions: Particle Theory of Matter
 Instructional Plan
 Access Prior Knowledge
Ask: What are mixtures? What are not mixtures? List some mixtures. List substances
that are not mixtures (pure substances).
Have students discuss these questions in pairs or small groups using a placemat activity
and record their ideas. To do a placemat activity, students fold a sheet of paper into
halves or fourths (depending on number of students in the group). All at the same time,
each student puts what they think and know in their section of the sheet. They can write
in words and/or draw pictures. Students share their ideas with other members of their
group.
Placemat: folds shown with dotted lines
Each student writes their ideas in
one section of the sheet.
Have students share their answers with the class. Make a large class T-chart so ideas
may be revisited in other lessons. These ideas may include facts, characteristics and
examples of mixtures and pure substances. (Accept misconceptions; do not attempt to
correct students at this time. Students may, however, convince each other to change
their minds. Look at the tips for facilitating class discussion on pages 19-20)
mixtures
not mixtures
Provide labels for students to look at the ingredients of various products (for example:
food, clothing). Items with more than one ingredient are mixtures; if there is only one
ingredient then the item is a pure substance. These labels can be added to the T-chart.
Post student versions of curricular outcomes on chart paper (see page 22).
Inform students that these outcomes will be addressed over the next portion of
the unit. Point out to students which outcomes are being addressed in each
activity.
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Mixtures and Solutions: Particle Theory of Matter
1
st
Cycle
 Curriculum Outcomes
109-7 Identify different approaches taken to answer questions, solve problems, and
make decisions.
112-7 Provide examples of how science and technology affect their lives and their
community.
209-6 Use tools and apparatus safely.
210-16 Identify new questions and problems about mixtures that arise from what is
learned.
307-2 Identify and separate the components of mixtures.

Have a class discussion: Ask: Why would people want to separate mixtures?
What mixtures get separated in real life and how are they separated?

Have students write a journal entry about the separation of mixtures in real life
 Assessment:
Can students determine real life situations where it is useful to separate mixtures?
Some examples of separating mixtures in the real world include:
sorting change to roll coins
to obtain desired minerals from mined ore
filtering and treating water/sewage
cleaning up oil spills in the ocean
sorting recyclable materials
separating blood into plasma, red blood cells, and so on
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Mixtures and Solutions: Particle Theory of Matter
 Separating Mixtures Activity
The focus of this activity is different methods of separating mixtures and introducing the
definitions of heterogeneous and homogeneous mixtures.
Materials:
Different tools for separating each mixture such as tweezers, plastic cups, forks,
magnets, filter paper, bowls, colanders, and spoons.
Different types of mixtures of two or three items
Possible separation methods and examples of mixtures:
Separation method
Colander
or containers with different sized holes
Scooping with slotted spoons or forks
Magnetism
Decanting (carefully pouring a solution
from a container in order to leave the
precipitate in the bottom of the original
container)
Evaporation
Floating, dissolving, static (using a
balloon)
Filtration
Manually (by hand)
Not easily separated
Example of mixture
Rice and beans
Marbles and tennis balls
Cheerios® and Rice Krispies®
Styrofoam peanuts and water
Metal nuts/washers and rubber bands
Iron filings and water
Cooking oil and water
Salt and water
Salt and pepper
Sand and water
Different colour or size beads
Different colour bread ties
Salt and sugar
Vinegar and water

Students working in small groups are presented with three or four different
mixtures from the list in the materials section. (Each group should have 1 or 2
different mixtures in common with other groups, and 1 or 2 mixtures which are
unique to them. This will allow some comparison during the post activity
discussion.)

Students are first asked to examine the mixture, writing down their descriptions
of the properties of the mixture – what do the constituents of the mixture looks
like, what shape are they, what colour are they, are they hard or soft, etc.
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Mixtures and Solutions: Particle Theory of Matter

Using a three quarter foldable, each student will draw a picture and label the
parts for one of their mixtures (with visible components). Make the foldable by
folding a sheet of paper into fourths and cutting the top left quarter off. (see
diagram)
 After cutting off the top left quarter,
students will draw a picture and label the parts for
this same mixture.
Students need to be made aware

Students should attempt to separate each mixture in
turn, using whatever method they feel will be most
successful. They can use some of the apparatus
provided or devise their own method, although
these should be discussed with a teacher prior to
using them for safety reasons.

Students indicate their separation method and draw the different components of
the separated mixture under the flap of the folded paper. Both the back of the
flap and the bottom fourth may be used.

For all their assigned mixtures, students should record what method(s) they used
for separation and how successful their attempts were.

Compared to the uses of the original mixture, what is different about the ways we
can use the separated components of the mixture? Explain.
New Brunswick Science Resource Package: Grade 7
that inability to separate a mixture
is not being unsuccessful.
Negative results give important
information to scientists and
should not be considered a waste
or failure.
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Mixtures and Solutions: Particle Theory of Matter
 Assessment:
During student activity, make notes on outcomes (or parts of outcomes) you
observe being addressed. Process skill outcomes are part of the curriculum and
should be assessed. Using the observation chart or the checklist (on page 25-27)
on a clipboard may be helpful to you. This is sometimes called clipboard cruising.
Develop your own code for quick notes.
A suggested code:
√
observed and appropriate,
WD
with difficulty,
RTT refused to try,
A
absent.
This chart may be used on multiple days, using a different coloured pen or pencil
each day and putting the date in the corner. You may not have a symbol or note for
every child every day. Some teachers like to focus on a group or two each time.
However you choose to make note of your observations, you will always have a
sense of who you need to take more notice of and who might need extra support.
The information will also help you when it is reporting time.
Options for storing foldables:
 in a large zippered plastic bag. The bag can be hole-punched and put inside
a duotang or binder. A strip of wide tape folded over the left edge of the bag
before punching the holes will keep the bag from ripping.
 glue into notebooks or duotangs
 display them on bulletin boards
 Reflection: Class Discussion

Students will share which mixtures they had and the method used to separate their
mixtures with the other groups. Taking the mixtures one at a time, ask questions like:
Did your group have this mixture? How did you separate it? Did anyone separate it a
different way? Were any other mixtures separated using that method?

Revisit the T-chart on mixtures (see page 5). Ask: Are there any items that should be
added to or revised. Is there other information we could add? Remind your class about
respectful discussion. See the tips on page 19-20.

Question for the class: Can everything be separated?

This video clip made by NB grade 7 students describes distillation as a method of
separating a mixture https://studycasts.wikispaces.com/Distillation
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Mixtures and Solutions: Particle Theory of Matter

Reflection: Individual
After discussion, have individuals write a journal entry. Can everything be separated?
Explain.
 Assessment:
Journal entries should not receive a score or mark. A positive comment followed by a
question to refocus attention or suggest the next step in learning is very effective.
Read journal entries to determine students’ understanding of mixtures - consist of two
or more components, components may be easy to distinguish or not, and the
properties of the components may make them easy to separate or very difficult to
separate.
 Think like a scientist
Asking good questions is an important skill in science. Initially students will need
support. Model the skill with the whole class and students will begin to have the
confidence to contribute. After some practice, students will be able to generate
questions successfully individually.
Present students with a situation and ask them to generate questions that could be
investigated scientifically. (These situations and questions do not have to be limited to
those that can be done in a classroom.)
Situation:
Canadian Blood Services collects donations of blood from the public and makes
blood products available to hospitals. In some cases whole blood is not needed
and patients are given platelets, red blood cells, plasma, or another component
found in blood.
Write a question concerning the separation of blood into useful components that
could be investigated scientifically.
For example:
Would a coffee filter separate one or more components from the rest of blood?
What is the ratio of the different components in blood?
New Brunswick Science Resource Package: Grade 7
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Mixtures and Solutions: Particle Theory of Matter
2
nd
Cycle
 Curriculum Outcomes
209-3 Use instruments effectively and accurately for collecting data.
209-6 Use tools and apparatus safely.
307-1 Distinguish between pure substances and mixtures, using the particle model of
matter.
307-2 Identify and separate the components of mixtures.

Introduce the idea of heterogeneous and homogeneous materials.
Heterogeneous mixtures – more than one type of material observable in the
mixture and not uniformly spread throughout.
Homogenous– appears to be one substance spread uniformly throughout. One
set of properties will describe all components of the mixture.
This video created by Grade 7 students may be helpful
https://studycasts.wikispaces.com/Homogeneous+Mixtures

As a class, and using the drawings from the last activity, sort the mixtures from Cycle 1
into heterogeneous and homogeneous mixtures. (If students could observe the
components and separate them, the mixtures would be heterogeneous.)

Make a list of products used every day in the kitchen. (dish soap, hand soap, cooking oil,
lemon juice, ketchup, salsa).
Ask students to classify the items as homogeneous or heterogeneous.

 Heterogeneous or Homogeneous Activity
In small groups:
Have students work in groups to explore and classify the following (or mixtures/solutions
similar to these) as homogeneous or heterogeneous.
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Mixtures and Solutions: Particle Theory of Matter
Materials:
At least 3 of: orange juice with pulp; chicken noodle soup; homogenized milk;
salsa; relish; jam; soda water; chocolate chip cookie.
Plus at least 3 of: shampoo; toothpaste; mustard; Kool-Aid; ketchup; dish
detergent.
Glass or clear plastic containers
Magnifying glasses
Microscopes or dissecting scopes
Dropper
Slides and cover slips if available
Flashlight
For each sample, the students:
 make observations without any optical aid and sort the containers into 2 groups
 make observations using a hand magnifier. Are there any samples they would
reclassify?
 Using microscopes (if available), have the students decide if there are some samples in
the solutions group that they should look at more closely. Are there any samples they
would reclassify?
 Assessment:
On observation chart (or other record), note how students are performing on the skill
outcomes.
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Mixtures and Solutions: Particle Theory of Matter
To record their results, students could use a layered book.
Layered book instructions:
Fold one sheet of paper
unevenly so there is a flap




Fold a second sheet more
unevenly
Place the folds inside each
other to create 4 layers.
Then cut up the middle of
the top 3 layers to create
flaps.
The top flaps can be labelled: heterogeneous mixtures,
homogeneous mixtures (solutions).
The second layer would list the mixtures on the
appropriate side using observations with the eye –
drawings or reasons for classifying the mixture could be
required
The third layer would list the mixtures on the appropriate
side using a hand lens - drawings or reasons for changing
a classification could be required
The fourth layer would list the mixtures on the appropriate side using the
microscope - drawings or reasons for changing a classification could be required
Note: Remind students that reclassifying an item when seen under higher
magnification doesn’t mean they were wrong the first time. As technology improves
and we are able to see smaller and smaller things, scientists’ understanding changes.
This sometimes results in changing models and theories.
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Mixtures and Solutions: Particle Theory of Matter
 Reflection: Class discussion

Facilitate a discussion about what students observed and their reasoning for
reclassification of mixtures as greater magnification was used.

Here is a video clip made by grade 7 students about the differences between
heterogeneous and homogeneous mixtures
https://studycasts.wikispaces.com/Beverage+Lab+-+Homogeneous+and+Heterogeneous

Revisit the T-chart on mixtures (see page 5). Ask: Are there any items that should be
added to or revised. Is there other information we could add? Remind your class about
respectful discussion. The tips on pages 19-20 may be helpful.
 Assessment:
Mixtures foldable can be collected. Note classification of materials and whether
observations with increased magnification resulted in changes.
New Brunswick Science Resource Package: Grade 7
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Mixtures and Solutions: Particle Theory of Matter
3
rd
Cycle
 Curriculum Outcomes
307-1 Distinguish between pure substances and mixtures, using the particle model of
matter.
307-3 Describe the characteristics of solutions, using the particle model of matter.
 Activity – Smaller than the eye can see
1. In small groups, have students brainstorm and record a list of the smallest things
they can think of. Each group can organize their items from largest to smallest. You
could have students print ideas on index cards or on pieces of paper with markers.
(These can be tacked to a bulletin board as they are shared.)
2. Then as a whole class, share one item that is the “smallest item” from each group
(round robin style) and record on the board or on chart paper. As each item is
named, decide where the item fits in the list of largest to smallest. Those items that
no other group has can earn that group a point.
Note: Even if students say atoms or molecules as their first item, work to elicit items of
different sizes to try to help students conceptualize how small particles are. Parts of the
atom, such as protons, electrons and/or neutrons may also be named, but not all
students will be able to visualize these. This activity also provides an opportunity to
discuss how the cell is the smallest unit of life and that it also is made of smaller
particles.
Option: Powers of 10 video – famous video to help demonstrate size and scale. It can
be found on YouTube at http://www.youtube.com/watch?v=A2cmlhfdxuY but if that link
is removed at some point, the official website is www.powersof10.com where the video
can be watched but it requires an e-mail address registration to be accessed. There is
no charge at this time.
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Mixtures and Solutions: Particle Theory of Matter
 Activity – Matter’s Particles
Revisit a variety of the heterogeneous and homogeneous mixtures (solutions) from the
first two cycles.
To contrast mixtures and pure substances:
1) a) Refer to the diagram students drew in Cycle 1 of one of their mixtures and the
separated components (page 8). Introduce students to the particle model of matter
by having them imagine the particles (molecules). Choose one of the heterogeneous
mixtures and ask students to re-draw and label the diagram of their “chosen”
solution from Cycle 2 showing how the particles are distributed. This diagram
should have different types of particles spread randomly and irregularly throughout.
b) Now have them re-draw a diagram of their separated components showing how
the particles are distributed. This diagram should have one type of particle.
Students should use the terms heterogeneous, mixture and pure substance.
To contrast homogeneous and heterogeneous mixtures:
2) Choose one of the heterogeneous mixtures from Cycle 2. Draw and label a diagram
of the heterogeneous mixture showing how the particles are distributed.
3) Choose one of the homogeneous mixtures (solutions) from Cycle 2. Draw and label
a diagram of the solution showing how the particles are distributed.
 Assessment:
Student diagrams For heterogeneous mixtures, is there more than one type of particle identified and are
the particles spread randomly throughout the mixture?
For homogeneous mixtures, is there more than one type of particle identified and are
the particles spread evenly throughout?
 Reflection: Class discussion


Have a class discussion highlighting the types and distribution of particles in the pure
substances and heterogeneous and homogeneous mixtures.
Revisit the T-chart on mixtures (see page 5). Ask: Are there any items that should be
added to or revised. Is there other information we could add? Remind your class about
respectful discussion.
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Mixtures and Solutions: Particle Theory of Matter
 Reflection: Journal
1. What characteristics are necessary for a material to be considered a pure
substance?
2. What characteristics are necessary for a mixture to be considered a heterogeneous
mixture?
3. What characteristics are necessary for a mixture to be considered a homogeneous
mixture (solution)?
 Assessment:
Journal entries should not receive a score or mark. A positive comment followed by a
question to refocus attention or suggest the next step in learning is very effective.
When reading the journal entries, note which students are getting the idea of the
differences between pure substances and mixtures and heterogeneous and
homogeneous mixtures.
Possible Extensions:
Give students the choice of one of the following:
1) Draw a cartoon that demonstrates your understanding of what happens to particles
during dissolving.
2) Create and act out a brief skit or interpretive dance that demonstrates your
understanding of what happens to particles during dissolving.
This site shows a representation of salt dissolving:
http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/thermoc
hem/solutionSalt.html
This links to a clip of salt dissolving:
http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf
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Mixtures and Solutions: Particle Theory of Matter
Possible Next Steps:
Take an in-depth look at the differences between soluble and insoluble in terms of
attraction between particles, and examples of solutes and solvents.
Introduce and use vocabulary and possibly reinforce with simple diagrams:
solution, solute, dissolving, solvent, soluble, insoluble
Have the students dissolve sugar in water.
Questions (Have the students work in small groups to discuss these questions):
What happens in terms of particles?
Imagine the particles. Where are the particles?
What are the particles doing?
What are the particles looking like?
Have students diagram dissolving, labelling solute, solvent, insoluble
This video clip made by NB grade 7 students may be helpful
https://studycasts.wikispaces.com/Solute+and+Solvent+-+Dissolving
And
https://studycasts.wikispaces.com/Soluble+and+Insoluble
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Mixtures and Solutions: Particle Theory of Matter
Supporting Class Discussion
No one person is as smart as all of us together.
Page Keeley, in the book “Science Formative Assessment” (2008), uses the analogy of
ping-pong and volleyball to describe discussion interaction. Ping-pong represents the
back and forth question-answer pattern: the teacher asks a question, a student answers,
the teacher asks another question, a student answers, and so on. Volleyball represents
a different discussion pattern: the teacher asks a question, a student answers, and
other students respond in succession; each building upon the previous student’s
response. Discussion continues until the teacher “serves” another question.
A “volleyball” discussion encourages deeper student engagement with scientific ideas.
Students state and give reasons for their ideas. Through the interaction, ideas may be
challenged and clarified. Extensions and applications of ideas may arise as well.
Discussions should avoid the personal and always revolve around ideas,
explanations and reasons. The goal is for students to achieve better understanding.
Share the ping-pong and volleyball analogies with your students. Good discussion takes
practice. You and your students will improve. Many teachers find discussion works best
if all students can see each other, such as in a circle, at least until they become
accustomed to listening and responding to each other.
As the teacher, you will need to:
o establish and maintain a respectful and supportive environment;
o provide clear expectations;
o keep the talk focused on the science;
o carefully orchestrate talk to provide for equitable participation.
It is important to establish discussion
norms with your class. Your expectations
may include:
o
Everyone has a right to participate and
be heard.
o
Everyone has an obligation to listen
and try to understand.
o
Everyone is obliged to ask questions
when they do not understand.
o
The speaker has an obligation to
attempt to be clear.
At first, discussions are apt to seem somewhat
artificial. Initially, a bulletin board featuring
cartoon talk bubbles with suggested sentence
starters may be helpful.
New Brunswick Science Resource Package: Grade 7
I respectfully disagree . . .
I had a different result . . .
Could you show how you got that
information?
When I was doing ___, I found that . . .
Even though you said ___, I think . . .
The data I have recorded in my
notebook is different from what you
shared. I found . . .
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Mixtures and Solutions: Particle Theory of Matter
It is helpful if teacher questions refer to a big idea rather than specifics. (Could
humans and chickens move their bones without muscles?) Questions should be
phrased so that anyone can enter into the conversation. Opinion questions are
especially good for this (What do you think . . . ?
How do you think . . . ? What if . . . ? Why . . . ?).
Provide plenty of wait time for students. Students give more detailed and complex
answers when given sufficient wait time. Allow wait time after student responses. When
students are engaged and thinking, they need time to process other responses before
contributing. If the discussion is not progressing, have students engage in partner talk.
Partner talk enables the teacher the opportunity to insert “overheard” ideas.
Helpful teacher prompts:
1. What outcome do you predict?
2. Say more about that.
3. What do you mean by . . . ?
4. How do you know?
5. Can you repeat what ____ said in another way?
6. Does anyone agree or disagree with . . . ?
7. Does anyone want to add to or build on to . . . ?
8. Who understands ___’s idea and can explain it in their own words?
9. Let me see if I have got your idea right. Are you saying . . . ?
10. So you are saying that . . .
11. What evidence helped you to think that?
12. Okay, we do not agree. How does each position fit the evidence? What else could
we find out?
References:
Keeley, Page (2008). Science Formative Assessment. Thousand Oaks, CA: Corwin
Press and Arlington, VA: NSTA Press
Michaels, Sarah, Shouse,Andrew W., and Schweingruber, Heidi A. (2008). Ready, Set,
SCIENCE! Washington, DC: The National Academies Press
New Brunswick Science Resource Package: Grade 7
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Mixtures and Solutions: Particle Theory of Matter
Materials List
Different tools for separating each mixture such as:
tweezers, plastic cups, forks, magnets, filter paper, bowls, colanders, and
spoons.
Different types of mixtures of two or three items – some of:
rice and beans
marbles and tennis balls
Cheerios® and Rice Krispies®
styrofoam peanuts and water
metal nuts/washers and rubber bands
iron filings and water
cooking oil and water
salt and water
salt and pepper
sand and water
different colour or size beads
different colour bread ties
salt and sugar
vinegar and water
At least 3 of:
orange juice with pulp; chicken noodle soup; homogenized milk; salsa;
relish; jam; soda water; chocolate chip cookie.
At least 3 of:
shampoo; toothpaste; mustard; Kool-Aid; ketchup; dish detergent.
Glass or clear plastic containers
Magnifying glasses
Microscopes or dissecting scopes
Droppers
Slides and cover slips if available
Flashlight
Grade 7 Science kits given to schools in 2009 contain:
2 tweezers/forceps
2 flashlights with batteries
2 magnet wands
8 magnifying glasses/hand lenses
8 pipettes/droppers
50 slides
50 cover slips
1 conductometer
8 thermometers
New Brunswick Science Resource Package: Grade 7
22
Mixtures and Solutions: Particle Theory of Matter
Student Version of Outcomes
109-7 Tell different ways that questions are answered,
problems are solved or decisions are made
112-7 Tell how science and technology affects your life
and community
209-3 Use instruments accurately for collecting data.
209-6 Use instruments and materials safely
210-16 Write new questions about mixtures that could
be investigated scientifically.
307-1 Use the particle model of matter to explain the
difference between pure substances and
mixtures.
307-2 Identify and separate the components of
mixtures
307-3 Describe the characteristics of solutions, using
the particle model of matter
New Brunswick Science Resource Package: Grade 7
23
Mixtures and Solutions: Particle Theory of Matter
Separating Mixtures
Examine each mixture and describe the properties (such as shape,
colour, odour, hardness) of each material that makes up the mixture
in the table.
Choose one of your mixtures that has 2 or 3 visible materials. On a
separate piece of paper, draw the mixture and label the parts.
Using the available materials, devise and carry out a way to separate
each mixture. Start with the mixture you drew a picture of. Once the
mixture has been separated, draw a picture of the components.
Mixture
Properties of the mixture
New Brunswick Science Resource Package: Grade 7
Method of Separation
24
Mixtures and Solutions: Particle Theory of Matter
Heterogeneous or Homogeneous
Activities
Materials:
Mixtures provided by your teacher
Magnifying lens
Microscope
Slides and cover slips
Dropper
Flashlight
Table or foldable to record observations
Procedure:
For each sample:
1) Make observations without any optical aid and sort the containers into 2 groups –
heterogeneous and homogeneous. Record the results on your table or foldable.
2) Make observations using a magnifier. Are there any samples that should be
reclassified? Group the mixtures and record your results.
3) If available, decide if there are some samples in the homogeneous group that should
be examined more closely. Take a drop of the mixture, drop it on a slide. Use another
slide or a cover slip and examine under the microscope. Repeat this step 3 times, taking
samples from different parts of the container. Are there any samples that should be
reclassified? Group the mixtures and record the results.
4) Shine a flashlight through each mixture. Can you see the beam of light in the
mixture? If you can, it means there are little bits floating in the mixture, causing the light
to scatter inside the solution. The mixture is likely heterogeneous.
Remember: Reclassifying an item when seen under higher magnification doesn’t mean
you were wrong the first time. As technology improves and we are able to see smaller
and smaller things, scientists’ understanding changes and models and theories change
too.
New Brunswick Science Resource Package: Grade 7
25
Mixtures and Solutions: Particle Theory of Matter
Observation Chart Sheet
Outcomes:
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
name
New Brunswick Science Resource Package: Grade 7
26
Mixtures and Solutions: Particle Theory of Matter
Checklist Sheet
Outcomes
STSE
109-7 Identify different
approaches taken to answer
questions, solve problems, and
make decisions
112-7 Provide examples of how
science and technology affect
their lives and their community
SKILLS
209-3 use instruments
effectively and accurately for
collecting data
209-6 Use tools and apparatus
safely
210-16 Identify new questions
and problems about mixtures
that arise from what is learned
KNOWLEDGE
307-1 Distinguish between pure
substances and mixtures, using
the particle model of matter
307-2 Identify and separate the
components of mixtures
307-3 Describe the
characteristics of solutions,
using the particle model of
matter
Correlations with
Cycles
1st cycle: Journal entry on pre-activity
discussion; mark/record observations
during Separating Mixtures activity and
class discussion; foldable; journal entry;
Think Like a Scientist response
1st cycle: Mark/record observations
during pre-activity discussion; Think Like
a Scientist response
2nd cycle: Mark/record observations
during pre-activity and activity; foldable
1st cycle: Mark/record observations
during Separating Mixtures activity
2nd cycle: Mark/record observations
during activity
1st cycle: Mark/record observations
during class discussion; Think Like a
Scientist activity
2nd cycle: Mark/record observations
during pre-activity, activity and class
discussion; foldable
3rd cycle: Mark/record observations
during the activity and class discussion;
student diagrams; journal entry
1st cycle: Mark/record observations
during Separating Mixtures activity and
class discussion; foldable; Think Like a
Scientist response
2nd cycle: Mark/record observations
during pre-activity, activity and class
discussion; foldable
3rd cycle: Mark/record observations
during the activity and class discussion;
student diagrams; journal entry
New Brunswick Science Resource Package: Grade 7
Yes
No
names
New Brunswick Science Resource Package: Grade 7
307-3 Describe the characteristics of
solutions, using the particle model of
matter
307-1 Distinguish between pure
substances and mixtures, using the
particle model of matter
307-2 Identify and separate the
components of mixtures
210-16 Identify new questions and
problems about mixtures that arise
from what is learned
209-6 Use tools and apparatus safely
209-3 use instruments effectively and
accurately for collecting data
112-7 Provide examples of how
science and technology affect their
lives and their community
109-7 Identify different approaches
taken to answer questions, solve
problems, and make decisions
27
Mixtures and Solutions: Particle Theory of Matter
Observation Checklist
28
Mixtures and Solutions: Particle Theory of Matter
Student Record
Outcome goal
Evidence
I can tell different ways that questions are
answered, problems are solved or decisions are
made.
I can tell how science and technology affects my
life and community.
I can use instruments accurately for collecting
data.
I can use instruments and materials safely.
I can write new questions about mixtures that
could be investigated scientifically.
I can use the particle model of matter to compare
pure substances and mixtures.
I can identify and separate the components of
mixtures.
I can describe the characteristics of solutions,
using the particle model of matter.
New Brunswick Science Resource Package: Grade 7