Download CChemical Reactions and Radioactivity

Chemical Reactions and
Radioactivity
C
EDCI 767 Curriculum and Instruction in
Secondary School Science
2009
Table of Contents
RATIONALE AND OBJECTIVES: CHEMICAL REACTIONS AND
RADIOACTIVITY (C4/5)
3
RATIONALE FOR ASSESSMENT TOOLS:
5
UNIT OVERVIEW: GRADE 10 PHYSICAL SCIENCE – CHEMICAL REACTIONS
(C4) AND RADIOACTIVITY (C5)
7
FULL LESSON PLAN #1:
9
LESSON #1 – THE LAW OF CONSERVATION OF MASS
9
FULL LESSON PLAN #2:
12
APPENDIX 1:
APPENDIX 2:
APPENDIX 3:
APPENDIX 4:
APPENDIX 5:
APPENDIX 6:
APPENDIX 7:
APPENDIX 8:
15
18
19
20
21
22
23
25
Rationale and Objectives: Chemical Reactions and Radioactivity (C4/5)
According to the British Columbia’s Science 10 Integrated Resource Package (IRP),
the purpose of science education is to provide opportunities for students to develop
scientific knowledge, skills, and attitudes that will be relevant to their everyday lives
and their future careers. Furthermore, the Science 10 curriculum is designed to allow
students to examine basic concepts, principles, laws and theories through scientific
inquiry while actively gaining the knowledge, skills and attitudes that provide the
basis for sound and ethical problem solving and decision making, among other
things.
A clear understanding of chemistry will contribute immensely to the goals of Science
10 outlined by British Columbia’s IRPs (as briefly described above), in that
knowledge of basic laws, principles, and concepts in chemistry will provide students
with a basis for understanding mechanism behind many aspects (that are usually
more complicated) from our day-to-day lives. For example, student acquisition of
knowledge regarding the nature of chemical reactions and how they are based on
the law of conservation of mass and the various types of chemical reactions will
provide with a basis from which they can predict the outcomes of reactions. This is a
skill that is useful when cleaning up chemical spills, such as bleach, in the home.
Student understanding of how rates of reaction can be affected or altered can be
used to explain why an egg undergoes a chemical reaction (cooks) in boiling water
but not in lukewarm water. Additionally, students can apply their knowledge of
radioactivity in their understanding of how different medical procedures and
diagnostic tools work, or understand why it is important not to handle radioactive
material without proper protection. In short, students will be able to use the
knowledge gained from Chemical Reactions and Radioactivity explain or predict
outcomes of everyday occurrences.
In addition to providing the students with knowledge that can be used in their day-today lives, the Chemical Reactions and Radioactivity unit will also grant students with
the most basic principles in chemistry that may be required in their future academic
or vocational pursuits. For instance, if a student was to continue on in science during
post-secondary schooling, it is necessary for them to have a basic understanding of
the principles of chemistry such as the law of conservation of mass and have basic
chemistry-related skills such as writing and balancing equations for Chemistry
courses (obviously), but also for courses in Biology and Physics. An understanding of
the mechanism behind radioactivity would be useful for students who decide to
pursue careers in nuclear power, nuclear medicine or even nuclear warfare
(hopefully not). Moreover, basic chemistry skills and being able to predict and write
balanced equations are also important in several careers including, but not limited
to: environment-related careers such as environmental engineering, chefs/bakers,
construction/plumbing, researchers, automobile mechanics, etc.
Clearly, the content of the Chemical Reactions and Radioactivity unit will provide
students with a knowledge base that will most likely be useful to them in the future.
However, a number of other skills will be learned during the course of this unit that
will not be directly related to specific skills or concepts in chemistry. For example,
during the course of this unit, students will demonstrate responsibility, cooperation
and respect for their peers as well as for the laboratory materials and equipment that
will be used during experiments. During class exercises, students will learn to work
effectively individually as well as in groups, respect the contributions of others, and
keep an open mind. In addition, by performing laboratory experiments in this unit,
students will enhance their understanding of the scientific method as well as their
ability to apply it to questions that are relevant to this topic. Students will develop
appropriate hypotheses, assist in the design of experimental procedures to test these
hypotheses, record observations and measurements in their lab books, and use these
observations to draw conclusions by making comparisons across groups.
Based on the above rationale, the following objectives for student learning and
understanding in this unit were developed from the suggested achievement
indicators:
1. SWBAT recognize that mass is conserved during physical changes and
chemical reactions (C4).
2. SWBAT define and explain the law of conservation of mass (C4).
3. SWBAT represent the law of conservation of mass in chemical reactions using
molecular models (C4).
4. SWBAT write and balance chemical reactions using the lowest whole
coefficients from formulae, word equations, or descriptions of experiments
(C4).
5. SWBAT identify the following types of reactions: synthesis, decomposition,
single and double replacement, neutralization and combustions (C4).
6. SWBAT give evidence for, predict products of, and classify the following types
of chemical reactions: synthesis, decomposition, single and double
replacement, neutralization and combustion (C4).
7. SWBAT explain how factors such as temperature, concentration, presence of a
catalyst and surface area can affect the rate of chemical reactions (C4).
8. SWBAT define isotope in terms of atomic number and mass number, and
recognize how these are communicated in standard atomic notation (C5).
9. SWBAT relate radioactive decay to changes in the nucleus (C5).
10. SWBAT relate protons, neutrons, electrons alpha and beta particles to
radioactive decay (C5).
11. SWBAT explain half-life wither reference to rates of radioactive decay.
12. SWBAT compare fission and fusion (C5).
13. SWBAT complete and balance nuclear equations to illustrate radioactive
decay, fission and fusion (C5).
14. SWBAT demonstrate safe lab procedures (A1).
15. SWBAT perform experiments using the scientific method (A2).
16. SWBAT demonstrate ethical responsible, cooperative behavior (A5).
Rationale for Assessment Tools:
In addition to “traditional” forms of assessment such as paper and pencil quizzes and
worksheets, we will also be incorporating a journal into our students’ daily routine
within our class. This journal will be used as a source of formative assessment
throughout the course of instruction. At the end of each class or lesson, students will
be given five minutes to answer the following questions in their journal:
1. What was one thing that you learned in Science 10 class today?
2. Was there one concept/idea that was confirmed during this lesson (something
that you already knew before the lesson began)?
3. What is one thing that you are unclear about?
4. Any further questions?
The teacher will collect the journals at the end of the lesson and use them to gauge
the level of student understanding so that adjustments can be made to the instruction.
Furthermore, this reflection can help students’ awareness of what they know and
what they still need to learn.
The Chemical Reactions Unit (C4) and the Radioactivity Unit (C5) requires student
understanding of not only new concepts, but also new ways of representing chemical
reactions (equations). Because of the nature of this unit, students require a lot of
practice questions (repetition) in order to fully grasp the skill. Therefore, multiple
worksheets will be given to the students throughout the course of this unit in order to
provide them with sufficient practice. Additionally, students should also be given the
opportunity to go back and correct their mistakes, rather than just leaving them as is
and moving on. Thus, at the beginning of each class, students will be given the
opportunity to mark their own worksheets (self-evaluate), and then will be allowed to
make any required corrections to their worksheets before they hand them into the
teacher the following day. The teacher can then use these worksheets to evaluate
student progress in addition to the amount of effort and improvement that is
observed. The grades for all worksheets, lab reports, quizzes, and tests will be
recorded in the students journal so that the student can make connections between
their effort in class and on homework assignments to the quiz and test scores.
Students also have workbooks to go along with textbooks and some assignments will
just be marked for completion because it’s a nice break for students to not be
marked on every single activity they do.
Laboratory assessment will be done mainly through the use of lab reports that will be
handed in to the teacher after completing the lab experiment during class. Each
student will be provided with a checklist of what needs to be included in the lab
report. For example, most lab reports will include:
1. Introduction – a brief introduction to the experiment with justification as to
why you are doing it
2. Hypothesis
3. Materials/Methods
4. Observations – data tables
5. Analyses – equations, calculations, graphs etc.
6. Results/Conclusions – analysis of possible errors.
The lab reports will be assessed on several levels including completion, accuracy,
neatness and correctness. The lab report will be used as an opportunity to formally
assess students on how they behave in a lab setting. Furthermore, it will also be used
to gage their understanding of different aspects of the scientific method (scientific
literacy).
Quizzes will be basic paper-and-pencil quizzes. After the quizzes have been
corrected, they will be returned to the student and the student will be allowed to
make corrections outside of class. An extra 5-10% will be added to the quiz grade if
the student completes his or her corrections. This will motivate students to learn from
their mistakes, rather than just letting them go.
Lastly, the final unit test will be a paper-and-pencil test and the questions will look
similar to those seen on previous Science 10 provincial exams. This method was
chosen in order to help students prepare for their Science 10 provincial exams at the
end of the semester.
Unit overview: Grade 10 Physical Science – Chemical Reactions (C4) and Radioactivity (C5)
Lesson #
1
2
3
4
5
Title
Law of Conservation of
Mass
Conservation of Mass
in Chemical Reactions
Types of Chemical
Reactions I
Types of Chemical
Reactions II
Rates of Reaction
Objectives
SWBAT recognize that
mass is conserved during
physical changes and
chemical reactions
SWBAT define and explain
the law of conservation of
mass based on their inclass concept invention
SWBAT identify &
balance the following
types of reactions:
synthesis,
decomposition, single
& double replacement,
neutralization,
combustion
SWBAT balance the
different types of
reactions.
SWBAT give evidence for,
predict products of, and
classify the following types
of chemical reactions:
synthesis, decomposition,
single and double
replacement, neutralization
and combustion
SWBAT define reaction
rate.
SWBAT explain how
factors such as
temperature,
concentration, presence of
a catalyst, and surface
area can affect the rate of
chemical reactions
Concept
SWBAT represent the
law of conservation of
mass in chemical
reactions using
molecular models.
SWBAT write and
balance chemical
reactions using the
lowest whole
coefficients from
formulae, word
equations, or
descriptions of
experiments.
-Writing and
balancing chemical
reactions
-Law of Conservation of
Mass
-Conservation of atoms
-Measuring masses of
reactants and products
Conservation of Mass
-Recognizing types of
chemical reactions
-Writing and balancing
chemical reactions
-Predicting products based
on the type of chemical
reaction
-Writing and balancing
chemical equations
-Reaction Rate
-How factors can affect
reaction rates.
Topic
Continuity
Write/Balance Equations for Different Types of Chemical Reactions
Rates of Reaction
Activities
-Conservation of Mass
Exploration activity (see
Appendix 1).
-Conservation of Mass
Teacher Demo (see
Appendix 1).
-Play-Doh Activity (See
Appendix 2).
-Element Inventory
-Review balancing
equations.
-In class questions on
types of chemical
reactions with review.
-Worksheet (App.4)
-Quiz – Balancing different
types of chemical
equations (ind).
-Alka-Selter Lab
Experiments 1,2 and 3
(http://www.alkaseltzerpl
us.com/asp/student_expe
riments.html)
Type of
assessment
-Conservation of Mass
Problem Exploration
(Completion)
-Lab Book
-Journal
-Lab Book Corrections
-Element Inventory
Worksheet (IC,
Appendix 3).
-Journal
-EI Worksheet
Corrections.
-Worksheet (Appendix
4)
-Journal
-Worksheet Corrections
-Quiz (IC) and corrections
(OC).
-Balancing practice
questions from text.
-Journal
-Lab Report (Intro,
Materials, Observations,
Analysis, Conclusions).
-Lab Book
-Journal
Unit overview: Chemical Reactions (C4) and Radioactivity (C5) Continued
Lesson #
6
7
8
9
10
Title
Introduction to
Radioactivity
Radioactive Decay: the
Nucleus and the
Subatomic Particles
Half-Life and Radioactive
Decay
Comparing
Fission/Fusion and
Balancing Nuclear
Equations
Unit Review: Chemical Reactions
and Radioactivity
Objectives
SWBAT define isotope in
terms of both atomic
number and mass
number
SWBAT how to recognize
and communicate
isotopes in standard
atomic notation
SWBAT relate
radioactive decay to
changes in the nucleus
SWBAT relate
subatomic particles
including (proton,
neutron, electron,
alpha/beta particle) to
radioactive decay
SWBAT explain half life with
reference to rates of
radioactive decay
SWBAT compare
Fusion and Fission
SWBAT balance
nuclear equations that
illustrates fission,
fusion and radioactive
decay
SWBAT understand what the
major concepts of the unit are and
prepare for the exam in a more
focused manner
Concept
-Learning the
definition/structure of
isotope and atomic
notation.
-Understand
radioactive decay in
terms of changes in the
nucleus
-Understand the role of
subatomic molecules in
radioactive decay
-Understanding Radioactive
Half-Life in terms of decay
-Understanding both
Fission and Fusion
- Writing and
Balancing Nuclear
Equations
-Major Concepts covered in
Chemical Reactions and
Radioactivity will be reviewed
Topic
Continuity
Isotopes/Nomenclature
Radioactive Decay
Fission/Fusion
Activities
- Subatomic particle
review followed by
online game that
requires class
participation (Appendix
5)
- Molecule modeling
activity (Appendix 5)
-Worksheet (Appendix
6)
i) What changes in the
nucleus during
radioactive decay
ii) Relationship
between subatomic
particles and
radioactive decay
- Radioactive Decay and Half
Life Simulation Activity
(Appendix 7)
- Balancing nuclear
equations in
workbook
- Review how to balance
Chemical and Nuclear Equations
- Review major concepts and
objectives of unit
- Practice and work through exam
“like” questions with the class
- Open lab time to do online
review and quizzes (Appendix 8)
Type of
assessment
-Participation
- Journal
-Worksheet completion
- Journal
-Lab Report (Intro, Materials,
Observations, Analysis,
Conclusions)
-Journal
-Worksheet
corrections
(Radioactive Decay)
-Journal
-Worksheet completion
(Balancing Nuclear Equations)
-Journal
Full Lesson Plan #1:
Lesson #1 – The Law of Conservation of Mass
PLOs covered in this activity:
 Demonstrate safe procedures (A1).
 Demonstrate ethical, responsible, cooperative behavior (A5).
 Demonstrate competence in the use of technologies specific to
investigative procedures and research (A7).
 Analyze chemical reactions, including reference to conservation of
mass and rate of reaction (C4).
Measurable Outcomes:
 SWBAT define and explain the law of conservation of mass (C4).
 SWBAT to recognize that mass is conserved in both physical and
chemical reactions (C4).
 SWBAT identify appropriate equipment for a lab activity (A1).
 SWBAT describe and demonstrate ethical behavior, open-mindedness,
willingness to question and promote, skills of collaboration and
cooperation, respect for the contributions of others (A5).
 SWBAT select and carefully use balances and other measurement tools
(A7).
Materials:



















Balance
Metric rule
Magnifying glass
Thermometer
Beaker with warm water
English walnut
Hammer
Paper Towels
Ziploc bags
Ice
Rubber Stopper
25g rock salt
Graduated cylinders
Play-Doh
Bunsen Burner
Test tubes
Lead nitrate solution
Sodium iodide solution
Ammonium nitrate







Hot plate
Flask
Popcorn Kernels
Rubber balloon
New/old flash bulb
Matches
Erlenmeyer flask
Time
15 min.
Cons. Of Mass
Exploration
Activity
(See Appendix
1 for activity
details)
20 min.
Cons. Of Mass
Concept
Invention
(See Appendix
1 for full details)
Students will:
- Be divided evenly
amongst the 5 stations and
will perform the
experiment at their station
and record the results in
their lab book.
- One representative from
each group will write the
observation from their
group on the board.
- Clean up.
- Participate in class
discussion.
- Attempt to come up with a
definition/explanation for
the law of conservation of
mass.
30 min.

Teacher Demo


(See Appendix
1 for full
details).
15 min.
Wrap Up
Observe teacher
demos.
Ask questions.
Participate in
discussion.
- Hand in the lab book for
marking (completion).
- Answer the daily
questions in their journal
and hand to the teacher
before leaving class.
Teacher will:
- Divide the class evenly
amongst the 5 stations by
numbering everyone off (15).
- Circulate through the class
while groups are working
and encourage groups to use
their balance during the
course of the experiment.
- After all observations are
reported, attempt to get the
class to come to a consensus
about what the 5 stations all
had in common.
- Ask them what was one thing
that remained the same
before and after each
transformation?
- If no one answers, see if you
can get them to focus on the
mass for each system.
- Discuss common errors that
may have occurred
throughout the course of the
experiment.
 Perform demos as outlined
in Appendix 1.
 Encourage student
participation by asking
questions to the class such
as “What do you think will
happen to the mass after
we …?”
- Debrief: law of conservation
of mass
- Ask the students to consider
how we can apply the law of
conservation of mass to
chemical reactions?
Assessment:
-
-
Because this is the first lesson of this unit, all assessment will be informal.
However the students’ ability to behave appropriately in a lab setting
during the Exploration Activity, cooperate with their peers, and participate
in discussion will be noted.
Student journal entries will be used as formative assessment to ensure that
the students learned what they were supposed to learn during the course
of the lesson.
Benefits of the Lesson:
-
-
-
Students have the opportunity to derive a definition/explanation of the law
of conservation of mass experimentally, which will enhance their
understanding of the concept, in contrast to just memorizing the definition.
Bottom-up learning style – students will see multiple examples of how
mass in conserved even during a chemical or physical change and from
this they will be able to derive their own definition of the law of
conservation of mass.
Understanding the law of conservation of mass is crucial to many aspects in
chemistry as well as in other scientific facets including: balancing chemical
equations, balancing nuclear reactions, water or nitrogen cycles in biology
etc.
This lesson and its inclusive exercise/discussions will help the student firmly
grasp the law of conservation of mass.
Full Lesson Plan #2:
PLOs covered in this activity:
 Demonstrate safe procedures (A1).
 Demonstrate ethical, responsible, cooperative behavior (A5).
 Demonstrate competence in the use of technologies specific to
investigative procedures and research (A7)
 Explain radioactivity using modern atomic theory (C5)
Measurable Outcomes:
 SWBAT to work along with others in a respectful and co-operative
manner (A5).
 SWBAT to define an isotope, use proper atomic notation (C5)
 SWBAT to create molecular models (C5)
Materials:
Laptop
Projector
Screen
Plastic-foam balls
Pipe cleaners
Red pushpins
Green pushpins
Beads
Coat hangers
Fishing line
Scissors
Time
5 min.
Students will:
- Listen to teacher
- Give quick overview of the
radioactivity section and how
lessons will be broken up
- Show students examples where
knowledge of radioactivity can
be useful (careers, industries,
inventions etc)
- Listen to teacher for
review lecture time
- Participate in review
game (protons, neutrons,
electron for elements) by
raising hand, calling out
answer
- Listen to teacher lesson
introducing radioactivity
- Participate in answering
questions, asking
question or any
comments
- Review the three subatomic
particles
- Play online game with glass to
get ready for introduction to
radioactivity (See Appendix 5
for link)
- Participate in
Constructing Atoms
Activity (see Appendix 5)
- Introduce activity and show
diagrams
- Organize Constructing Models
Activity (materials, groups)
- Help as needed during activity
- Answer any questions required,
ask questions to challenge
students
- Do quick wrap up
- Give time for journal writing
Overview
and Real Life
Applications
10 min.
Review
25 min.
Introductory
Concepts of
Radioactivity
30 min.
Constructing
Atoms
Activity
10 min.
Wrap Up
Teacher will:
- Listen to wrap up
- Journal writing
- Use PowerPoint to teach lesson
on what an isotope is, how to
properly communicate using
atomic notation, mass number
and atomic number of isotopes
- Ask questions to engage class
regarding an elements proton,
neutron and mass number
Assessment:
-
-
Being the first lesson of this unit, assessment will be informal.
The students’ ability to behave appropriately in a lab setting during the
activity as well how well they cooperate with their peers, and participation
in the discussion will be noted.
Student journal entries will be used as formative assessment to ensure that
the students learned what they were supposed to learn during the course
of the lesson.
Benefits of the Lesson:
-
-
Students have the opportunity to create and be able to better visualize
atoms/isotopes thereby better understanding the concept, in contrast to
just memorizing the definition.
Review session on subatomic particles will help students refresh their
memory and since it is such a basic concept for chemistry it will help in
really drilling it into their brains for future use
Appendices:
Appendix 1:
Conservation of Mass – Adapted from The Physical Science Activities Manual, Center of
Excellence for Science and Mathematics Education at The University of Tennessee at Martin,
http://www.utm.edu/departments/cece/cesme/psam/PSAM/psam8.pdf
Problem Presentation/Exploration:
Each group will be assigned to a station and given 4-5 minutes per station to
observe the outcome of the specified activity and make as many
measurements as they can think of. Tell the students that after they have been
to all the lab stations that they will be asked to figure out what each activity
had in common, or what happened to each case that was the same.
Station Setup:
1. Station #1:
a. Materials: balance, a metric tule, a magnifying glass, a
thermometer, a beaker with warm water, an English walnut, a
hammer
b. Directions: “Without opening the Ziploc bag, break the walnut by
hitting it with the hammer.”
2. Station #2:
a. Materials: balance, a metric rule, a magnifying glass, a
thermometer, a beaker with warm water, paper towels, a sealed
Ziploc bag containing an ice cube.
b. Directions: “Melt the ice cube by putting the Ziploc bag containing
the ice cube into the beaker of warm water.”
3. Station #3:
a. Materials: balance, a metric rule, a magnifying glass, a
thermometer, a beaker of warm water, a sealed Ziploc bag with two
sealed test tubes inside. One test tube will contain a solution lf lead
nitrate and the other will contain sodium iodide. When mixed
together they will produce a bright yellow solid.
b. Directions: “Without unzipping the bag, uncork the tops of the two test
tubes and allow their contents to pour out into the bag. DO NOT UNZIP
THE BAG.”
4. Station #4:
a. Materials: balance, a metric rule, a magnifying glass, a
thermometer, a beaker of warm water, a sealed Ziploc bag
containing 25mL of water and a sealed bottle with 5 grams of
ammonium nitrate in it.
b. Directions: ‘Without unzipping the bag, unstopper the bottle and
allow the sold to come in contact with the liquid in the bag. Shake the
bag. DO NOT UNZIP THE BAG.”
5. Station #5:
a. Materials: balance, a metric rule, a magnifying glass, a
thermometer, a beaker of warm water, a hot plate, a filter flask fitted
with a rubber stopper, two kernels of popcorn, a rubber balloon.
b. Directions: “Place the popcorn in the filter flask. Place the rubber
stopper back into the flask. Attach the balloon to the side arm of the
filter flask. Place the apparatus on the hot plate and leave it there until
the kernels pop.”
Class Response / Concept Invention:
A. Have each group report its findings on an observation sheet. Have one
member of the group transfer the group’s findings to an appropriate
table on the board.
B. After all groups have reported their observations, try to get the class to
come to consensus about all the things that the five activities had in
common. Possibly they will try to draw conclusions on the basis of
physical and chemical reactions, but this is not what they all had in
common. If they can’t agree on the common event, ask them what one
thing remained the same, before and after each transformation, for the
materials at each lab station. If no one mentions the use of the balance,
see if you can get them to concentrate on the mass of each system.
C. Assuming that there might be some measurement error that might
make the conclusion harder to visualize, work with the class to see if
they can come up with the idea that the mass remained constant in both
the physical changes as well as in the chemical changes. Common
errors might be weighing the system when it is either colder or hotter
than before the transformation. Some students might not carefully dry
the Ziploc bags after they have been in the water. Reading the balance
wrong will probably take care of itself since more than one student in a
group will probably be involved in the massing process. Also, all
groups will be carrying out the activities and the repetition of data can
serve to point out erroneous measurements. The observation that the
mass remains constant throughout a chemical or physical reaction is
generally known as The Law of Conservation of Mass. Another way of
looking at this law is that no matter is destroyed during a a chemical or
physical reaction.
D. Because some of the exploration activities carried out by the groups
may not have utilized the balance to its fullest benefit, a few more
activities where the Law of Conservation of Mass can be experienced
may be needed to reinforce the concept.
a. Examine a new flash bulb and one that has been flashed. Which
one looks like it has a greater mass? (Most students would say
the used one because it has additional products of oxidation
visible.) Put a new bulb on the balance and record its mass. Flash
the bulb, let it cool, and put it back on the balance. The mass
should remain constant.
b. A similar demonstration would be to put two or three kitchen
matches into a 500 mL Erlenmeyer flask and tightly stopper it
with a rubber stopper. Put on a balance and determine the mass
and record it. Remove the flask from the balance and carefully
bring a Bunsen burner close to the flask so that the heat will
come in contact with the matches in the flask and ignite.
CAUTION: Heat only for a short time. Extreme caution should be
used whenever a closed container is heated. After cooling back to
room temperature return the flask to the balance and record its
mass. Have students predict what the mass will be. [Once again,
the mass should be the same. The flask must cool before
determining its mass.]
c. Next demonstrate three situations where by mixing two
substances together it may appear that mass is disappearing.
i. Place 25 g of rock salt in a 100 mL graduated cylinder.
Carefully fill the cylinder to the 100.0 mL mark with water,
put a rubber stopper in the mouth of the cylinder, and
place it on a balance. Record its mass. Take the cylinder
off the balance; shake it vigorously until all the rock salt
has dissolved. Observe the level of solution now in the
cylinder. Where has the missing liquid gone? What should
the students predict will be the mass when it is now put
back on the balance? [The mass should remain constant.
As the salt dissolved, the ions mixed between the spaces
of the water particles and the volume decreased slightly.]
ii. Into one 100 mL graduate cylinder place 50 mL of water.
Into another 100 mL graduate cylinder place 50 mL of
alcohol (ethyl alcohol works best). Place both graduated
cylinders on a balance and record the mass. Now, slowly
pour the contents of cylinder #2 nto cylinder #1. Place
both graduated cylinders back on the balance. Notice the
combined volume and the total mass. Once again the mass
is conserved but the volume shrinks.
iii. You will need three identical balances and three balls of
Play-Doh®. Each of the balls of Play-Doh® must have the
same mass. While the students are watching flatten one of
the balls out into a pancake. Roll the other one out
lengthwise and join one end to the other end to make a
doughnut. Now, have the students predict which one has
the greatest mass. Even though Piaget says that students in
your class should have developed to the point that they
can conserve mass, it might be interesting to see if some
still think that the altering of the shape has altered the
mass.
Appendix 2:
Play-Doh Activity
Materials: Play-Doh (red, yellow, blue), toothpicks, PowerPoint Presentation
Directions:
 After teaching the students how chemical reactions are written
(reactants on left side of the arrow, products on the right side of the
arrow) remind the students of the law of conservation of mass and that
the number of atoms of one element on the left side of the reaction must
equal the number of atoms of the same element on the right side of the
reaction.
 Present the students with the following reactions:
i. Al + O2  Al2O3, (red=Al; blue=O)
ii. CH4 + O2  CO2 + H2O (red = C; yellow = H; blue = O)
iii. H2 + N2  NH3 (yellow=H; blue = N)
 Have the students model the equations using the Play-Doh and
toothpicks (bonds).
 Ensure that the students have the same number of each element on
either side of the reaction equation.
 Have the students count how many of each element are required on
each side of the equation to determine the appropriate coefficients.
 Ask the students to write the balanced equation on the board.
Appendix 3:
Element Inventory Worksheet
(Adapted from http://misterguch.brinkster.net/eqnbalance.html)
Make element inventories and balance the following equations:
1. __NaCl + __BeF2 --> __NaF + __BeCl2
2. __FeCl3 + __Be3(PO4)2 --> __BeCl2 + __FePO4
3. __AgNO3 + __LiOH --> __AgOH + __LiNO3
4. __CH4 + __O2 --> __CO2 + __H2O
5. __Mg + __Mn2O3 --> __MgO + __Mn
Appendix 4:
Balancing Chemical Equations Worksheet
1. What side of a chemical equation are the reactants on? The products?
2. Balance and state the type of reaction: H2 + N2  NH3
3. Balance and state the type of reaction: C3H8 + O2  CO2 + H2O
4. Balance and state the type of reaction: Al + CuO  Al2O3 + Cu
5. Balance and state the type of reaction: K2O + H2O  KOH
6. Meena reacted hydrochloric acid with sodium hydroxide to form sodium
chloride and water. Write the balanced equation and state the type of
reaction.
7. Methane gas burns in the presence of oxygen gas to form carbon dioxide
and water vapor. Write the balanced equation for the combustion of
methane.
Appendix 5:
A) Subatomic Particle Review
Review subatomic particles (protons, neutron, electrons) and how they relate
to each other followed by an online game in which an element is flashed on
the front screen and students are encouraged to participate in answering the
questions.
Review game is found online at http://education.jlab.org/elementmath/
b) Molecular Modeling Activity
http://www.cvs.k12.mi.us/jdurand/LabModelingAtoms.pdf
Appendix 6:
i) Radioactive Decay Worksheet (Adapted from
http://www.gcsescience.com/prad37-radioactivity-questions-answers.htm)
Radioactive Decay
1) What is Radioactive Decay?
2) During Radioactive Decay, what can a Nucleus Emit?
3) Is Radioactive Decay a Random Process?
4) How can a Nucleus be Unstable?
5) How can an Unstable Nucleus change into a more Stable form?
6) What is the relationship between protons, neutrons and electrons and
radioactive decay?
Alpha Particles
a) What does an Alpha Particle consist of?
b) How is an Alpha Particle written?
c) What happens to the Mass Number when an Alpha Particle is emitted?
d) What happens to the Atomic Number when an Alpha Particle is emitted?
Beta Particles
a) What does a Beta Particle consist of?
b) How is a Beta Particle written?
c) What happens to the Mass Number when a Beta Particle is emitted?
d) What happens to the Atomic Number when a Beta Particle is emitted?
e) What does a Neutron in the Nucleus become when a Beta Particle is
emitted?
Gamma Rays
a) What does a Gamma Ray consist of?
b) How is a Gamma Ray written?
c) What happens to the Mass Number when a Gamma Ray is emitted?
d) What happens to the Atomic Number when a Gamma Ray is emitted?
e) What happens to the Nucleus when a Gamma Ray is emitted?
Appendix 7:
Radioactivity Half Life (Adapted from
http://www.utm.edu/departments/cece/cesme/psam/PSAM/psam37.pdf)
1) PROBLEM PRESENTATION
A. Lets investigate how long it would take to spend a million dollars. There is
only one rule we will follow in this exercise. On each day you can only
spend half of what you start the day with. So on the first day you get to
spend a half million dollars.
1. Question: "If on January 1 you start with one million dollars, on what day
will you end up with only one dollar or less?
2. How long do you think it will take to spend the million dollars: Two
days? A week? A month? A year? A decade?
3. The following table may help in figuring out how long it would take.
Date
Starting Amount
Ending Amount
Jan 1
Jan 2
Jan 3
Jan 4
Jan 5
Jan 6
Jan 7
Jan 8
Jan 9
Jan 10
Jan 11
Jan 12
Jan 13
Jan 14
Jan 15
Jan 16
Jan 17
Jan 18
Jan 19
Jan 20
1 000 000.00
500 000.00
500 000.00
5. How long do you think it would take you to spend one hundred dollars
following the same rule?
Date
Jan1
Jan 2
Jan 3
Jan 4
Jan 5
Jan 6
Jan 7
Starting Amount
100.00
50.00
Ending Amount
50.00
6. In both of these cases we would say that the time it took to spend half of
what remained was one day. We call this the "half-life."
2) Exploration Activity
Pages 2-4:
http://www.utm.edu/departments/cece/cesme/psam/PSAM/psam37.pdf
Appendix 8:
Online Review & Quizzes
Chemical Reactions and Radioactivity:
http://www.bcscience.com/bc10/pgs/links_u2.html