Chemical and Human Resources, Part II
Lynne Martin, Maxfield Science, Math & Technology Magnet
School, St. Paul, MN
Kathy Scoggin, Marcy Open School, Minneapolis, MN
Our venture into history coupled activities for
both younger and older students in a unit on chemical and physical
changes. The younger children pursued an instructional unit
on "Mystery Powders." We
selected a several scientists appropriate
to the unit and told stories about the scientists during the
activities.
The older students conducted research to learn about
these and other scientists (both
personal and professional items of interest). We had them
look especially for how they could actually become that
scientist through role-playing. They also looked for a
lab activity they could do with younger students to illustrate
that scientist's work. They made a "big book" of
their scientists. Finally, the older children visited the
younger students, set up learning stations for them, conducted
historical scientific activities with
them, and shared their big book -- while playing the role
of the scientist throughout the activity.
Possible extension activities include:
- for the younger students: thank-you letters, a classroom
anthology of historical scientists, books about the experience
- for the older students: biographical research reports,
multimedia productions (videos of their role-playing?!),
a classroom anthology of historical scientists
Level: Grades K-6
This curriculum module was developed as part of a project
sponsored by Sci-Math-MN and The Bakken Museum and Library.
Click to see a directory of other
modules using history and philosophy of science.
Other Scientists
- ANDRE MARIE AMPERE
- ARCHIMEDES
- ARISTOTLE
- ROGER BACON
- BENJAMIN BANNEKER
- JOHN BARDEEN
- NIELS BOHR
- GEORGE WASHINGTON CARVER
- CHEN NING YANG
- COPERNICUS
- IRENE CURIE
- JOHN DALTON
- CHARLES DARWIN
- MARIE CURIE
- ALBERT EINSTEIN
- ELLEN RICHARDS
- MICHAEL FARADAY
- ENRICO FERMI
- SIR ALEXANDER FLEMING
- GALILEO GALILEI
- LLOYD AUGUSTUS HALL
- WILLIAM HARVEY
- ALEXANDER VON HUMBOLDT
- THOMAS HUXLEY
- SHIRLEY A. JACKSON
- ERNEST E. JUST
- ANTOINE LAVOISIER
- ELIJAH McCOY
- LISE MEITNER
- DIMITRI MENDELEEV
- SIR ISSAC NEWTON
- ALFRED NOBEL
- LOUIS PASTEUR
- IVAN PAVLOV
- MAX PLANK
- JOSEPH PRIESTLEY
- WILHELM RONTGEN
- MARY SCHWARTZ ROSE
- CHARLES HENRY TURNER
- CHENG YIN
There are others that you can find out about and research also.
To find historical scientists appropriate to the unit content
or skills:
- Call the science department college campus and find a likely
candidate who might give you the names.
- Call a high school science teacher for help.
- Contact your district science curriculum person and let
that person conduct the search for you.
- Find a good book on historical scientists and do it yourself!
Activities for Younger Students Led by Older Students
Set-up involves five stations to observe chemical and physical
changes and the idea of elements versus compounds, complementing
the earlier activities of the younger students:
- Yeast (temperature change and gas production during chemical
change)
- Red Cabbage Juice (acid-base color indicators of chemical
change)
- Inflating Balloon (physical change)
- Vitamin C (nutrient testing color change for chemical change)
- Marshmallow Models: Compounds and Elements (Dalton's atomic
models)
STATION #1 -- YEAST
OBSERVATION AND CHEMICAL REACTION
**Remember to talk about observation as a necessary skill in
science. Persistence and accuracy are very important also.
Remember that a chemical reaction occurs when we
see a temperature change, a solid coming out of a solution,
a color change, or gas production. In this case look for gas
production in both experiments and a temperature change in
the yeast and peroxide combination.
You have two experiments to do with your students:
- Mixing yeast with the hydrogen peroxide, and
- Combining a yeast and sugar mixture with different temperatures
of water to observe what happens.
- Have your students put water into each of the three test
tubes. Have the one on the left be for cold water, the middle
one for warm water, and the one on the right for hot water
- from the black tea pot.
- Have the students measure 1/2 teaspoon of the yeast and
sugar mixture into each of the three test tubes. (Use the
funnel for pouring more easily.)
- Put a thumb over the top of the test tube and gently wave
the liquid back and forth to mix it a little. Set aside while
you do the other experiment.
- Have the students measure a yellow spoonful of yeast into
a white film container. Add a blue spoonful of hydrogen peroxide
and watch the reaction. Be sure to pick up the container
also and feel the heat as the reaction occurs. A gas (oxygen)
is being produced in the bubbles and water is being left
behind with the yeast. Hydrogen peroxide is a compound of
hydrogen and oxygen.
- Look back to the yeast and sugar mixture in the test tubes.
Keep watching until you can observe the differences in the
reactions that the different temperatures of water cause.
Talk with the students about using yeast in a recipe and
how you would know what temperature of liquid to try and
add to yeast for the best results.
Teacher's Notes for Station #1 -- Yeast
Materials:
- dry yeast
- hydrogen peroxide
- sugar
- test tubes
- film containers - white worked especially well for observation
- measuring spoons
- test tubes
- water - cold, warm, hot
Procedures:
Experiment 1:
- Mix a equal mixture of sugar and yeast.
- Pour 1/2 teaspoon of the mixture into each of three test
tubes.
- Place the test tubes next to each other (we used 1 test
tube holder per group). Organize left to right for cold,
warm and hot water - or label.
- Pour 1/2 Tbsp. of the appropriate temperature of water
into each test tube. Swish gently back and forth to mix a
little. Observe and describe then set aside while you do
experiment #2.
- Go back and observe and describe again and then make hypothesis
regarding the use of yeast and appropriate water temperature
in baking. **This works best if you have at least 10-15 minutes
to let the reaction happen before making final observations.
Experiment 2:
- Place 1/4 teaspoon dry yeast in the film container.
- Pour 1/2 teaspoon hydrogen peroxide onto the yeast.
- You will see bubbling as the oxygen is released from the
hydrogen peroxide mixture (H2O2). Yeast catalyzes the breakdown
of hydrogen peroxide into oxygen and water. You will also
be able to feel the heat released in the reaction through
the sides of the film container.
STATION #2 -- RED CABBAGE JUICE
CHEMICAL REACTION STATION - ACID/BASE INDICATOR
A chemical reaction has occurred when we see
temperature change, formation of a precipitate, color change,
or gas production. In this case look for color change.
- Have the students put about 1/2 inch of the purple indicator
liquid in each of three test tubes. Use eyedroppers to do
this.
- Explain about acids and bases being opposites. Tell them
that vinegar is an acid and baking soda is a base.
- Using the eyedropper have the student put several drops
of vinegar into the test tube on the right. Notice the color
change. Compare to the tube in the middle which always stays
the same with nothing added to it.
- Using their fingers they should put a pinch of baking soda
in the test tube on the left. Notice the color change.
- Challenge them to figure out a way to change each of the
test tubes of liquid back to their original colors. (Help
them with ideas if necessary.)
Teacher's notes for Station #2 -- Acid-base Indicators
You will need:
- red cabbage
- vinegar
- baking soda
- plastic cups or test tubes
- eye droppers
- plastic ice cream bucket
- Soak torn up cabbage leaves - 3 or 4 leaves is plenty -
in hot water ( pour boiling water over) in the bucket for
up to 1 hour. This will be your indicator solution.
- Divide your indicator equally among 3 test tubes ( or cups).
Label one cup as your 'control'. Place this cup in the center
of the three and do not add anything to your control. Add
a small amount of vinegar (a few drops) to one of the tubes
of indicator and swirl. Compare the color of this indicator
to the color of your control.
- Now add a small amount of baking soda (a pinch) to the
other tube of indicator and swirl. Compare the color in this
tube to your control.
- If either of your indicators changed color, (and they should
have !) challenge the students to figure out what to add
to it to make it turn back to the color of the control.
STATION #3 -- INFLATING BALLOON
PHYSICAL CHANGE STATION
- Explain that a physical change occurs when something changes
from one form to another form. Discuss water: it can be a
solid, a liquid, or a gas. Ask the students to think of examples
of water in each of these forms.
- Have students place about 1/3 of an inch of water in the
test tube.
- Cover the test tube with a balloon.
- Carefully hold the test tube over the lit candle until
the balloon begins to inflate.
- Talk about why this happened. Have them try to tell you
first (The water molecules heated up and began to bounce
around and take up more space than they had before.)
Teacher's notes for Physical Change Station #3
Materials:
- test tubes
- small balloons
- water
- warming candles
- matches
- *an adult to be able to stay with this station at all times
for safety
Procedure: The children place about 1/3 of an inch of water in
the test tube. Cover the test tube with a balloon. Hold the test
tube over the lit candle until the balloon begins to inflate.
STATION #4 -- TESTING FOR VITAMIN C
CHEMICAL REACTION AND THE BIG BOOK OF SCIENTISTS
**Remember to talk about a chemical reaction as happening
when we see a temperature change, a color change, gas production,
or the formation of a precipitate (a solid from a solution).
- Have students measure about an inch of the starch and iodine
indicator solution in the test tube (pour from the measuring
cup to do this easily).
- Add drops of the Vitamin C solution one at a time - with
the eyedroppers - until you get the color to change.
- Discuss the color change as the evidence of a chemical
reaction.
- Share the book. The 'scientists' need to be the page turners
so that the least amount of wear and tear happens.
Teacher's notes for Chemical Reaction Station #4 (Testing
for Vitamin C)
Materials:
- cornstarch
- measuring spoons and cups
- saucepan (not aluminum)
- measuring devices (spoons, metric, etc,)
- vitamin C tablets
- water
- iodine
- test tubes or baby food jars
- eyedroppers
Procedure:
- First make a stock starch solution using 1/2 teaspoon cornstarch
and 1 cup water in a saucepan. Warm over low heat until the
cornstarch is completely dissolved. Pour into a jar, label
and cover. This will keep for a few days in the refrigerator.
- To make the test solution put 1 teaspoon of the stock starch
solution into a jar with 1 cup of water and 4 drops of iodine.
Label. This will be blue-black due to the reaction of starch
with iodine.
- Test the test solution using the vitamin C. Dissolve several
vitamin C tablets in 1 cup of water ( I used about 7 1000
mg tablets.) Put 1 or 2 tablespoons of the starch plus iodine
test solution into a test tube. Add 1 drop of the vitamin
C solution. The mixture should become colorless as the vitamin
C reacts with the iodine. -- if not add more drops of the
vitamin C solution as needed.
- **You can also test food samples such as tomato juice,
orange juice, pickle juice, lemonade powder, Tang, etc.
STATION #5 -- MARSHMALLOW MODELS
ELEMENTS AND COMPOUNDS
- Have students glue on one color of small marshmallows to
the first section of the chart to represent element A. No
more than 5 marshmallows are needed.
- Glue two large white marshmallows to the second section
to represent element B.
- In the third section glue two large white marshmallows
and four small (the same color as was used in the first section)
- but they should not touch at all.
- In the last section glue two large white marshmallows and
then glue two small colored - same color as before - right
next to the big ones to represent a compound.
- Talk over the theory with the group and then glue the white
sheets which explain Dalton's Atomic theory on to the back
of their sheets.
*Have everyone write their names on their sheets please.
Teacher's notes for Station #5
Dalton's atomic theory included the following ideas:
- All elements are composed of tiny indivisible particles
called atoms.
- Atoms of the same element are identical. The atoms of any
one element are different from those of any other element.
- Atoms of different elements can combine with one another
in simple whole number ratios to form compounds.
- Chemical reactions occur when atoms are separated, joined,
or rearranged. However, atoms of one element are not changed
into atoms of another by a chemical reaction.
Materials:
- large white marshmallows
- small colored marshmallows
- construction paper charts
(These were made by taking a regular sized
piece of construction paper, dividing it into four columns
and labeling the four columns (going across the paper
the long way) as: Atoms of element A, Atoms of element
B, Mixture of atoms of elements A and B, and Compound
of molecules made from uniting atoms of elements A and
B.)
- atomic theory sheets
Procedure: Marshmallows are glued onto the columns to represent
the various atoms:
- one color of small marshmallows as element A
- large white marshmallows as element B
- a mixture of the small (same color as in the first column)
and large white in the third column - make sure they do not
touch
- compounds in the fourth column -- illustrated by two small
colored marshmallows connected to one large
The atomic theory sheets were copied for each student and glued
on to the reverse side of the chart to be discussed.
Link to activities for younger students. |
