Julie Levine
January 25, 2012
The Mystery of the Missing Chocolate Chip Cookies/ Harry Potter Mystery
Teacher’s Kit
Time: 40 minutes
Age: 10-14
**Use the chocolate chip cookie mystery for younger students and the Harry Potter
mystery for older students.
**Depending on the age of the students, the clues in the beginning can be made to
point to two of the children rather than just one. This will make the mystery slightly
more challenging. This lesson can also be made more difficult by including more
suspects or adding more clues.
**Students will use a chart to cross off suspects and determine who is guilty.
I am providing two “mysteries” involving the same experiments and learning goals.
Version 1: The Mystery of the Mission Chocolate Chip Cookies
Three triplet brothers were all eating lunch in their kitchen. Their mom had made
all three of them the same peanut butter and jelly sandwiches and given them the
same Mentos candies for dessert. However, she had given each boy his favorite
drink. Mark likes Kool-Aid, Walter likes Coca-ColaTM, and Sean likes bubbly water.
The boys were troublemakers, and after eating their sandwiches, they began
throwing their Mentos candies at each other. The Mentos ended up inside each
of the boys’ cups. After the boys left the kitchen, their mom found out that one of
them had stolen all of the cookies from the cookie jar! Use the following clues and
experiments to determine who stole the cookies from the cookie jar.
1)
Clue 1: Right next to the cookie jar was a big foamy puddle.
Students will use an experiment (dropping Mentos candies into Kool-Aid,CocaColaTM, and seltzer/bubbly water to determine which boy’s or boys’ drink would
create a foamy mess when a Mentos candy was dropped into it.
Only the carbonated drink (the Coca-Cola or seltzer water) will create a foamy
explosion. The Coca-ColaTM has sugar in it, which will create an even larger foam
explosion. This evidence should incriminate Sean and Walter.
1
**Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
**This can be used to teach energy. The teacher could add to the worksheet
questions about potential energy and kinetic energy. The Mentos and Coca-ColaTM
have potential energy before they are placed together. Once they are added
together, then the energy becomes kinetic as the reaction occurs.
**Chemical vs. Physical reactions can also be discussed in relation to this
experiment.
2)
Clue 2: The boys’ mom noticed that one of her identical sons stayed behind
after the two other boys left and enjoyed a bowl of cereal after their sandwich. The
mom could not tell which one of the boys it was, but she did tell us her sons’ favorite
cereals. Sean likes Total and Walter and Mark both like Fruit Loops. We have
the cereal bowl that the boys left behind.
Students will use an experiment to determine the iron level of the cereal in the bowl
that was left behind as well as the iron levels of the boys’ favorite cereals.
The iron level of Total should be much higher than the Fruit Loops, and Sean
whose favorite cereal is Total should again look suspicious.
** Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
3)
Clue 3: A piece of shoelace was found on a nail on the floor next to the
cookie jar. The way the fabric is dyed looks a certain way. All 3 boys were wearing
shoes with blue shoelaces made of different materials. The students will dye the
different “shoe laces” (yarn) blue with cool-aid. The students will then compare the
dyed blue shoelaces with the one found to determine the thief.
This evidence should point towards Sean.
**Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
4)
Clue 4: The three brothers also like to write secret messages to each other on
gold paper (goldenrod color changing paper) that their mother has seen them spray
with blue liquid to reveal secret messages. One message must have fallen out
because one seemingly blank gold paper was found on the floor near the cookie jar.
Use an experiment to determine what the paper says. Use window cleaner to spray
the paper and reveal the message.
2
The message should reveal a note from Mark to Sean: “Dear Sean, I don’t think you
should steal the cookies! Mom will be mad! Love, Mark”
This evidence should again point towards Sean.
** Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
Materials Needed:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Kool-Aid mix
water
Coca-ColaTM/seltzer
cups for Mentos reactions
bins to keep cups in
Mentos
Fruit Loops
Total Cereal
beakers (50 or 100 mL) (this can be replaced with small Dixie cups. The
students can be told to fill the Dixie cups half way with cereal and to the top
with water)
10. Magnetic wand
11. Magnifying glass
12. Method of crushing cereal (Plastic baggies and filled soda bottles)
13. Goldenrod color changing paper
14. Golden crayon
15. Window cleaner
16. 3 different types of white yarn that look fairly similar (stapled/taped to an
index card and labeled by their owners)
17. Cups for dipping yarn into
18. Stirrer/plastic spoon
19. Paper towels
Preparations (20-25 Minutes):
Experiment 1: Have 3 cups set up inside a plastic bin, one with Kool-Aid, one with
seltzer, and one with Coca-ColaTM. For each of the three cups, give the students six
Mentos (they will put two Mentos in each cup and watch the reaction).
Experiment 2: Have the two types of cereal at this station along with a 50 mL beaker
or a Dixie cup and larger cup. Have the plastic bags and filled soda bottles
available for crushing the cereal. Have the magnetic wands available as well.
Experiment 3: Have a cup filled with water as well as Kool-Aid mix and a stirrer.
Staple or tape the evidence yarn onto an index card and write evidence on the card.
3
Staple or tape the 3 types of yarn to another index card and label the yarn with the
boys’ names. Sean’s shoelace should be the same as the sample.
Experiment 4: For this experiment, write, “Dear Sean, I don’t think you should steal
the cookies! Mom will be mad! Love, Mark” on goldenrod color changing paper.
Have a window cleaner spray bottle available for the students to reveal the message.
Version 2: Help Harry find who stole his Invisibility Cloak!
Harry Potter, Hermione Granger, Ron Weasley, Draco Malfoy, Neville
Longbottom and Luna Lovegood all enjoyed their dinner feast in the Great Hall
together after Harry returned from a long and dangerous journey with Hagrid.
However, after dinner, Harry realized that his invisibility cloak was missing! He
decided to return to the Great Hall to see if he could find any clues that would help
him determine who had stolen his cloak of invisibility. Can you help Harry use the
clues he finds to determine who the thief is?
1) Clue 1: Right next to where Harry had left the cloak was a big foamy puddle.
The Hogwarts house elves had made everyone the same roast beef sandwich
and gave everyone the same Mentos candy for dessert. However, they had given
each witch and wizard their favorite drink. Ron likes slug juice, Hermione likes
salamander eye juice, and Luna likes dog saliva. This was a very happy evening at
Hogwarts, and after eating their sandwiches they began playfully throwing their
Mentos candies at each other. The Mentos ended up inside each of the students’
cups.
Students will use an experiment to determine which drink would cause a foamy
puddle to form when a Mentos candy is dropped into it. This will be the first clue
to see who was near the cloak.
Only the carbonated drink (the Coca-ColaTM or seltzer water) will create a foamy
explosion.
This clue will point to Hermione and Luna.
**Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
**This can be used to teach energy. The teacher could add to the worksheet
questions about potential energy and kinetic energy. The Mentos and Coca-ColaTM
have potential energy before they are placed together. Once they are added
together, then the energy becomes kinetic as the reaction occurs.
2) Clue 2: Near the cloak, Harry also found a bowl of kidney pudding. Ron likes his
kidney pudding plain and Luna and Hermione like to add beetle bits to theirs. We
have the bowl that was left near the cloak.
4
Use an experiment to determine if there are beetle bits in the bowl that was left
behind.
Students will crush the Total cereal that is labeled “Kidney Pudding” and soak it in
water. They will use the magnetic wands to discover the “beetle bits” which are
actually metallic iron in the cereal.
This clue will point toward Hermione and Luna.
** Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
3) Clue 3: The cloak thread of the witch or wizard who stole the cloak got stuck on
a nail near where the cloak was hanging. However, Harry tripped when he found
this clue and spilled his blue drink on the thread. We have samples of the cloak
threads that everyone was wearing. Dye the samples blue to determine whose
cloak the thread came from.
Students will use Kool-Aid to dye the yarn blue. Ron and Hermione will have the
same yarn as the evidence yarn.
This clue will point to Ron and Hermione.
**Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
4) Clue 4: The magic world of Hogwarts also involves many secret messages. One
message must have fallen out of the thief’s pocket because a seemingly blank
gold paper was found on the floor near where the cloak was stolen.
Students will use an experiment to determine what the paper says.
The secret message will read, “Hermione, Did you get the invisibility cloak so that
we can spy on Professor Snape?”
This final clue will be the last piece of evidence used to incriminate Hermione.
This can be used to explain acid-base indicators. The goldenrod color changing
paper is made of a base indicator, and window cleaner is a base. The paper is
protected where the wax from the crayon covers the paper but turns red
everywhere else when sprayed with a basic solution.
** Maine Learning Results: Inquiry and Problem Solving, Scientific Reasoning,
Communication
Materials Needed:
1. Kool-Aid mix
2. Water
3. Coca-ColaTM
5
4.
5.
6.
7.
8.
9.
Seltzer
Cups for Mentos reactions
Bins to keep cups in
Mentos
Total Cereal
Beakers (50 or 100 mL) (this can be replaced with small Dixie cups. The
students can be told to fill the Dixie cups with cereal and to the top with
water)
10. Magnetic wand
11. Magnifying glass
12. Method of crushing cereal (sealable baggies and filled soda bottles)
13. Goldenrod color changing paper
14. Gold crayon
15. Window cleaner
16. 2 different types of white yarn that look fairly similar (stapled/taped to an
index card and labeled by their owners)
17. Cups or bowls for dipping yarn into
18. Stirrer/plastic spoon
19. Paper towels
Preparation (20-25 minutes):
Experiment 1: Have 3 cups set up inside a plastic bin, one with Kool-Aid, one with
seltzer, and one with Coca-ColaTM. The cups should be labeled:
Liquid
Kool-Aid 
Coca-ColaTM
bubbly water/seltzer
water
Label
Slug Juice
Salamander Eye
Juice
Dog Saliva
For the three cups, give the students six Mentos (they put two in each cup and
watch the reaction).
Experiment 2: Have the Total cereal labeled as “Kidney Soup.” For each group, have
a plastic bag and a soda bottle filled with water available for crushing the cereal.
Have the magnetic wands available as well. Dixie Cups or beakers should be here so
that the students can measure the water and cereal. A larger cup for combining the
cereal is also necessary.
Experiment 3: Have a cup filled with water and Kool-Aid mix to stir in. Have
stirrers available. Staple or tape the evidence yarn onto an index card and write
evidence on the card. Staple at least 2 or 3 different types of yarn to another index
card and label the yarn with the characters’ names. Hermione’s yarn should be the
same as the evidence.
6
Experiment 4: For this experiment, write “Dear Hermione, Did you get the
Invisibility Cloak so that we can spy on Snape?” on goldenrod color changing paper.
Have a window spray bottle available for the students to reveal the message.
This will be the last piece of evidence to incriminate Hermione.
Science Behind the Clues:
1. The Mentos candies act as a catalyst for the carbon dioxide present in
carbonated drinks to be released into the air. This is why only the
carbonated drinks create the foamy reaction.
2. Total cereal is a cereal rich in iron. Once the cereal is crushed and
soaked in water, the iron is released, and the magnetic wand can pick up
the pieces of iron. The Fruit Loops are not an iron rich cereal, so the
magnet will not pick up any metal.
3. The different threads are made of different materials, and each material
absorbs dye differently. For example, acrylic material repels more dye
than wool material.
4. This secret message is written on goldenrod color changing paper, which
is made of an acid and base indicator with a gold crayon. Where the gold
crayon wrote on the paper, the paper is protected from the window
cleaner. The window cleaner is basic, so when it is sprayed, the paper
turns to bright red except where the note was written, revealing the
message.
Learning Objectives:
1. This experiment involves combining multiple pieces of evidence to form a
conclusion. Deductive reasoning can be taught in this experiment.
2. Using scientific evidence rather than previous biases can be discussed in
relation to this experiment (especially the Harry Potter version). Many
students initially assume that Draco Malfoy stole the invisibility cloak
because he is the “bad guy,” but scientific evidence points to a different
suspect.
3. The characteristics of metals can be discussed in terms of the iron being
attracted to the magnet.
4. Different types of energy (potential and kinetic) can be discussed in
reference to the experiment with the Mentos and different liquids as well
as physical and chemical changes.
5. Properties of different materials can be discussed in terms of how different
fabrics dye.
6. Acid and base red-ox reactions can be discussed with the goldenrod paper as
well as indicators and color changes.
7
Clean Up (10 minutes):
The cups and bins from the Mentos reaction can be rinsed out and re-used. The
Mentos and liquids should be disposed of, as they cannot be reused for this
experiment. The Magnetic Wands and cups used for the second experiment will
need to be rinsed. The bottles and bags used for crushing can be reused if they were
not damaged. The index cards with the dyed yarn cannot be re-used, and the cup
used to dye the yarn will need to be rinsed. The table where the goldenrod paper
was sprayed will need to be wiped down. The paper can be reused for the same
experiment once it dries.
References:
Potential and Kinetic Energy,
http://www.energyeducation.tx.gov/energy/section_1/topics/potential_and_kineti
c_energy/index.html , January 6, 2012.
Goldenrod color changing paper can be ordered from Flinn Scientific Inc.
8
Student Worksheet- Version 1
Name_____________________________________________________
The Mystery of the Missing Chocolate Chip Cookies
Three triplet brothers were all eating lunch in their kitchen. Their mom had made
all three of them the same peanut butter and jelly sandwiches and given them the
same Mentos candy for dessert. However, she had given each boy his favorite
drink. Mark likes Kool-Aid, Walter likes Coca-ColaTM, and Sean likes bubbly water.
The boys were troublemakers, and after eating their sandwiches, they began
throwing their Mentos candies at each other. The Mentos ended up inside each
of the boys’ cups. After the boys left the kitchen, their mom found out that one of
them had stolen all of the cookies from the cookie jar! Use the following clues and
experiments to determine who stole the cookies from the cookie jar.
5)
Clue 1: Right next to the cookie jar was a big foamy puddle.
Use an experiment to determine which boy’s drink would cause a foamy puddle to
form when a Mentos candy is dropped into it.
Directions: Drop two Mentos candies into each of the three drinks, and fill in the
chart as to whether you see a foamy reaction.
Boy
Favorite Drink
Mark
Walter
Kool-Aid
Coca-Cola
Sean
Bubbly Water
Foaming Reaction?
9
Write/ explain which boy or boys this evidence you find points to.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
This experiment demonstrated two different types of energy. Potential energy is
stored energy. Kinetic energy is energy in motion. The Mentos and Coca-ColaTM
each have potential energy at one point and kinetic energy at one point during the
reaction. Explain when during the experiment the energy is transformed.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
6)
Clue 2: The boys’ mom noticed that one of her identical sons stayed behind
after the two other boys left and enjoyed a bowl of cereal after his sandwich. While
he was alone in the kitchen, the boys’ mom believes he took the cookies. The mom
could not tell which one of the boys it was, but she did tell us her sons’ favorite
cereals. Sean and Mark like Total cereal and Walter likes Fruit Loops cereal. We
have the cereal bowl that the boy who stayed behind left in the kitchen. The three
boys are all lactose intolerant (which means they can not drink milk because their
body can not digest it), so they all eat their cereal with water rather than milk.
Use an experiment to determine the iron level of the bowl that was left behind as
well as the iron levels of the boys’ favorite cereals. You can use these results to
determine which cereal was the one left behind and which boy it belonged to.
Directions: Pour 20 mL of each cereal into separate bags, so you have one bag with
Total and one bag with Fruit Loops. Seal the bags trying to get all of the air out.
Crush the cereals using your bottle filled with water. Measure 50 mL of water with a
beaker and pour the cereal into the beaker with the water. Allow the cereal to soak
in water for 5 minutes, stirring the whole time. During this time you should discuss
who you think the thief will be. After 5 minutes, use a magnetic wand and swirl it
through the cereal and water mixture; you will pick up iron on the wand if there is
any in the cereal. This is because iron is a metal, which is attracted to the magnet
(similar to why magnets stick to a metal refrigerator). Use a magnifying glass to
compare the levels of iron (black specs on the magnet) in the bowl that was left by
the cookie jar with the levels of iron in the boys’ favorite cereals. This will help you
determine which boy the cereal bowl belonged to. Which of the two cereals have
similar to or the same amount of iron as the mystery bowl? What can you conclude
about the mystery bowl? What cereal is it? Who did it belong to?
10
Boy
Favorite Cereal
Sean and Mark
Total
Walter
Fruit Loops
Mystery Bowl
Type of Cereal?
Iron
Present?
Write/ explain who this evidence points to.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
7)
Clue 3: The shoelace of the boy who stole the cookies got stuck on a nail in
the kitchen. We have samples of the laces that each boy was wearing. Dye the
samples blue to determine whose shoelace was found at the scene of the crime.
Directions: Mix together 100 mL of water and 1 packet of cool-aid in the beaker
provided. Then dip all of the strings into the cool-aid mixture one at a time for 10
seconds each. Pull the strings out, place them onto a paper towel, and determine
which sample the shoelace found looks the most similar to.
Write/ explain which boy this evidence you find points to.
__________________________________________________________
__________________________________________________________
__________________________________________________________
8)
Clue 4: The three brothers also like to write secret messages to each other on
gold paper that their mother has seen them spray with window cleaner to reveal
secret messages. One message must have fallen out of one of the brothers’ pockets
because a seemingly blank gold paper was found on the floor near the cookie jar.
Use an experiment to determine what the paper says.
Directions: Use window cleaner to spray the paper and reveal the message.
11
What does the message say?
__________________________________________________________
__________________________________________________________
CONCLUSION: Based on all of your evidence, who do you think stole the cookies?
__________________________________________________________
__________________________________________________________
12
Directions: As a suspect is ruled out, put an x in that box.
Boy
Clue 1
Clue 2
Clue 3
Clue 4
Sean
Mark
Walter
13
Student Worksheet- Version 2
Name_____________________________________________________
Help Harry find who stole his Invisibility Cloak!
Harry Potter, Hermione Granger, Ron Weasley, Draco Malfoy, Neville
Longbottom, and Luna Lovegood all enjoyed their dinner feast in the Great Hall
together after Harry returned from a long and dangerous journey with Hagrid.
However, after dinner, Harry realized that his invisibility cloak was missing! He
decided to return to the Great Hall to see if he could find any clues that would help
him determine who had stolen his cloak of invisibility. Can you help Harry use the
clues he finds to determine who the thief is?
9)
Clue 1: Right next to where Harry had left the cloak was a big foamy puddle.
The Hogwarts house elves had made everyone the same roast beef sandwich
and given everyone the same Mentos candy for dessert. However, they had given
each witch and wizard their favorite drink. Ron likes slug juice, Hermione likes
salamander eye juice, and Luna likes dog saliva. This was a very happy evening at
Hogwarts, and after eating their sandwiches they began playfully throwing their
Mentos candies at each other. The Mentos ended up inside each of the students’
cups.
Use an experiment to determine which drink would cause a foamy puddle to form
when a Mentos candy is dropped into it. This will be the first clue to see who
could have stolen the cloak.
Directions: Drop two Mentos candies into each of the three drinks. Fill in the
chart as to whether you see a foamy reaction.
Character
Favorite Drink
Ron
Hermione and Draco
Malfoy
Luna and Neville
Slug juice
Salamander eye juice
Foaming Reaction?
Dog Saliva
14
Write/ explain which student or students this evidence you find points to or who
you can rule out as a suspect based on this evidence.
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________
This experiment demonstrated two different types of energy. Potential energy is
stored energy. Kinetic energy is energy in motion. Explain if and when during the
experiment the energies were present and when the energy was transformed.
Slug Juice _____________________________________________________________
Salamander Eye Juice________________________________________________
Dog Saliva____________________________________________________________
10)
Clue 2: Near the cloak, Harry also found a bowl of kidney pudding. Ron likes
his kidney pudding plain and Luna and Hermione like to add beetle bits to theirs.
We have the bowl that was left near the cloak.
Use an experiment to determine if there are beetle bits in the bowl that was left
behind.
Directions: In order to see if there are beetle bits in the pudding left behind, we
have to soak the pudding in water. Pour ½ of a Dixie cup of the pudding into a
plastic bag. Seal the bag trying to get all of the air out. Crush the pudding using your
bottle filled with water. Measure one full Dixie cup of water and pour the cereal
and water into the larger cup. Allow the cereal to soak in water for 5 minutes,
stirring the whole time. During this time you should discuss who you think the thief
may be. After 5 minutes, use a magnetic wand and swirl it through the cereal and
water, you will pick up the beetle bits on the wand if there is any in the pudding.
Use a magnifying glass to determine if the beetle bits (black specs on end of wand)
are present.
Write/ explain who this evidence points to or who you can rule out based on this
evidence.
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
15
11)
Clue 3: The cloak thread of the witch or wizard who stole the cloak of
invisibility got stuck on a nail near where the cloak was hanging. However, Harry
tripped when he found this clue and spilled blue dye on the thread. We have
samples of the cloak threads that everyone was wearing. Dye the samples blue to
determine whose cloak the thread came from.
Directions: Mix together 1 Dixie cup of water and 1 packet of Kool-Aid in the cups
provided. Then dip all of the threads into the Kool-Aid mixture and let sit for 2
minutes. Pull the strings out and lay them on a paper towel to determine which
sample the thread found looks the most similar to.
Write/ explain which character this evidence indicates might be the thief.
________________________________________________________________
________________________________________________________________
________________________________________________________________
12)
Clue 4: The magic world of Hogwarts also involves many secret messages.
One message must have fallen out of the thief’s pocket because a seemingly blank
gold paper was found on the floor near where the cloak was hanging.
Use an experiment to chemically reveal what the paper says.
Directions: Because we do not have magic, we will use window cleaner to spray the
paper and reveal the message.
What does the message say?
__________________________________________________________
__________________________________________________________
__________________________________________________________
CONCLUSION: Based on all of your evidence, who do you think stole the magic
cloak?
__________________________________________________________
__________________________________________________________
16
Directions: As a suspect is ruled out, put an x in that box.
Suspect
Clue 1
Clue 2
Clue 3
Clue 4
Luna
Lovegood
Ron Weasley
Draco Malfoy
17
Neville
Longbottom
Hermione
Granger
18