Chemical and Human Resources, Part
I
Kathy Scoggin, Marcy Open School, Minneapolis,
MN
Lynne Martin, Maxfield Science, Math & Technology Magnet School,
St. Paul, 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 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.
Mystery Powders
The accompanying instructional unit focused on Minnesota Outcome
7:
Students will learn about the nature of atoms and
molecules and the structure of matter by observing patterns
in physical properties of objects for purposes of classification.
We adapted the ESS/SCIS Unit "Mystery Powders" for
our third graders (each investigation question is keyed):
- What is matter? (G3.1)
Learners will observe the physical properties of 5 powdered
solids.
- What happens when each powder is combined with water? (G3.2)
Learners will observe a physical change when water is added
to powdered solids.
- What powder properties can we observe by doing an iodine
test? (G3.3)
Learners will observe chemical changes when iodine is added
to powdered solids.
- What powder properties can we observe by doing a vinegar
test? (G3.4)
Learners will observe chemical change when vinegar is added
to powdered solids.
- How can we use our observation data to identify the white
powders? (G3.5)
Learners will enter data into a spreadsheet and identify
each powder.
Each of the five lessons is detailed below.
INVESTIGATION QUESTION G3.1
What is matter?
SUMMARY
Learners will observe the physical properties of 5 powdered solids.
MATERIALS
Per student pairs
Per teacher demo
- Set of materials
- Lab cam
- Laser disc PR Vol.3, Matter & Energy, Lesson 19
PROCEDURE
ACTIVATE
This unit on matter is an investigation into the properties of
5 solids we will call mystery powders. A quick review lesson
on physical properties will be necessary. Because we will be
working in the field of chemistry as we discuss physical and
chemical changes, a brief introduction to chemistry is appropriate
in this first lesson. The laser disc lesson on physical changes
provides good background for today's lesson.
DISCOVER
We will first need to discuss safety issues surrounding the
observation of unknown substances: never taste anything in
the science lab unless instructed to do so, how to smell
an unknown substance, washing hands after touching unknown
substances, the use of goggles to protect eyes, etc. Then
use the record sheet to describe how students observe physical
properties of the powders. We will observe color, texture,
and shape (hand lenses) and record our observations on the
record sheet.
INTEGRATE
Discuss observations. Based on these observations, let students
make hypotheses about the white powders. What do you think
each powder is? Why? What tests could we do to find out about
each powder?
Tell stories of scientists who investigated physical
properties of substances: John Dalton (see
Historical Chemists below).
INTEGRATIONS
Students find the study of chemistry very intriguing. They
enjoy mixing substances and observing reactions because
it feels like "real" science. It would be very
interesting to do some reading about chemistry and famous
chemists. Medical fields rely heavily on the practices and
discoveries of chemists around the world, as do environmental
scientists, ecologists, biologists, botanists, and many others.
Chemistry also has been the subject of great historical events
and debates. If you are interested in pursuing such topics
beyond our discussions in the lab, let me know. I have many
resources and materials to support you.
INVESTIGATION QUESTION G3.2
What happens when each powder is combined with water?
SUMMARY
Learners will observe a physical change when water is added to
powdered solids.
MATERIALS
Per student pair
Per teacher demo
- Laser disc PR,Vol .3, Matter & Energy , Lesson 19
- Set of materials for demo of procedure
PROCEDURE
ACTIVATE
Today we are putting the powders into solution: we will add water
to each. When we do this we will create a physical change in
our materials. The solution will look different than either material
did before we created the change, but nothing new is created
(during a chemical reaction, a new material is produced and the
old materials are indistinguishable). We still have water, we
still have the powders, but they are now in solution together.
The laser disc lesson helps explain physical change and can be
used in introduction or in the integration discussion.
DISCOVER
Monitor student activity for safe practices while using unidentified
substances. During clean up, solutions are safe for sink
disposal. Assign tables to 1 of the 3 sinks for disposal
and cleanup.
INTEGRATE
Discuss observations. What happened with a little powder and
a lot of water? A little water and a lot of powder? Were
there any differences among physical reactions? Could we
reverse these reactions back to dry powder and water? How?
It's important for learners to realize that physical changes
create nothing new. Cutting paper with scissors, using glue,
dissolving Kool-Aid powder into water, boiling macaroni noodles
are all physical changes.
Tell stories of scientists who worked with physical changes: Albert
Einstein and the atomic bomb (see Historical Chemists).
INVESTIGATION QUESTION G3.3
What powder properties can we observe by doing an iodine test?
SUMMARY
Learners will observe chemical changes when iodine is added to
powdered solids.
MATERIALS
Per student pair
Per teacher demo
- Laser disc PR,Vol.3, Matter & Energy, Lesson 20
- Materials for demo of procedure
PROCEDURE
ACTIVATE
Today we're going to learn about chemical change as change which
produces a completely new type of matter. The laser disc lesson
is a good introduction to the activity. Remind learners about
safety rules while working with unknown substances.
DISCOVER
Learners will place a small amount of powder in a mixing cup
and drop iodine on the powder, being careful not to touch
the powder with the dropper. They will need to observe and
record any changes that they see, including color, odor,
and temperature.
INTEGRATE
Discuss observations. Iodine is known to indicate a substance
called starch by causing a chemical reaction that turns it
black. Does this test give us any information about the identity
of the 5 powders? If a powder did not turn black after iodine
was added, what can we conclude about that powder? The black
substance is completely new matter that did not exist before
the iodine was added; therefore, the change that occurred
was a chemical change.
Tell stories of scientists who worked with chemical changes: Antoine
Lavosier (studied one of our mystery powders!), George
Washington Carver.
INVESTIGATION QUESTION G3.4
What powder properties can we observe by doing a vinegar test?
SUMMARY
Learners will observe chemical change when vinegar is added to
powdered solids.
MATERIALS
Per student pair
Per teacher demo
- Laser disc PR,Vol.3, Matter & Energy, Lesson 21
PROCEDURE
ACTIVATE
Today we're going to cause more chemical changes when we add
vinegar drops to each powder. The procedure is exactly like yesterday
so we'll be dropping vinegar onto each powder in a mixing cup.
Record and changes observed.
DISCOVER
Remind learners that they may observe temperature, textural,
color and odor changes.
INTEGRATE
Discuss observations. The most prominent reaction is the fizzing
of baking soda with vinegar, which also produces an odor
(a gas). Now we know that one of the powders is baking soda.
The laser disc lesson points out everyday ways that people
change matter physically and chemically to make it more useful
to them.
Tell stories of scientists who worked with chemical changes: Alfred
Nobel and his nitroglycerin.
INTEGRATIONS
The reading lab has a whole series of From...To... books that
each describe some process of change, physical and chemical.
There are many different ways these books could be used in
your reading curriculum. It would be interesting for learners
to read the books and determine whether the change described
is physical or chemical change. OUTCOME 7: Students will
learn about the nature of atoms and molecules and the structure
of matter by observing patterns in physical properties of
objects for purposes of classification.
INVESTIGATION QUESTION G3.5
How can we use our observation data to identify the white powders?
SUMMARY
Learners will enter data into a spreadsheet matrix and identify
each powder.
MATERIALS
Per student pair
Record sheets 1-4
Spreadsheet template (in PDF
file format) PROCEDURE
ACTIVATE
This lesson will be team taught by the technology integrator,
the classroom teacher, and the science integrator. The lesson
has 3 objectives:
- To collate data collected in chemistry lab all week into
a matrix
- To learn to use the spreadsheet component of word processing
- To conclude the
identity of the 5 mystery powders
We will not complete all three objectives in this one lab period
but will continue during Mac lab sessions following this one
until our matrix is complete.
DISCOVER
Learners will receive instruction in using spreadsheets. They
will then incorporate their own data into the spreadsheets.
They can also identify the powders and record from a posted
list.
INTEGRATE
From their data, we will
create property descriptions of each powder, i.e. baking
soda is a very fine white powder that fizzes with vinegar,
does not change with iodine, and doesn't mix well with water.
These descriptions represent both physical and chemical properties.
For most historical scientists, record keeping was laborious
at best. Learners now have the power of technology in that
we can collate our data onto a spreadsheet and print it out
instantly. Scientists of the past would be very impressed!
INTEGRATIONS
Other powders can be tested with iodine and vinegar. Perhaps
a homework assignment might include testing flour or cream
of tartar or baking powder with vinegar and recording observations.
The vinegar record sheet could be used as homework.
Historical Chemists
We focused on the following scientists and incorporated their
stories into our lab activities:
JOHN DALTON
1766-1844 Chemist from England who was born color blind. He
did the first important investigation to answer his own questions
about color blindness and published his conclusions for others
to learn from. He also developed the theory that all matter
(elements) are made of atoms. He said that each kind of matter
has its own kind of atoms, arranged in its own way. That's
why each kind of matter has its own special properties.
1864-1943 Black chemist and naturalist who didn't start school
until he was nine years old because he had no parents or money.
But he was determined to answer the questions he had about
how things work in nature. He was especially curious about
plants and he did many investigations with them. He discovered
lots of chemical changes that occur in plants, especially the
peanut plant and its fruit. His discoveries led to the development
of over 300 products that could be made from peanuts!
1879-1955 German chemist who was a quiet shy boy who loved
music and math. He was not a magnificent school learner but
he taught himself many things outside the classrooms he attended.
Most scientists didn't believe his first ideas about atoms
and physical changes in matter, and his work was shunned. But
later he was proven to be correct. All through his life the
ideas he wrote and spoke about were far ahead of what most
scientists believed. A champion of peace and a fighter of oppression,
this shy and gentle man made discoveries that lead to the development
of the atomic bomb.
1743-1794 French chemist who revolutionized the practice of
chemistry. He liked to study geology and rocks best. He was
particularly intrigued by one of the white powders we are studying,
plaster, and he spent a lot of time observing its properties.
His ideas about gas atoms were very different than what most
scientists believed at that time. In fact, he proved the most
widely believed property about gases to be wrong! His experiments
with the gas called oxygen led to chemical names we use today.
1833-1896 Swedish chemist who experimented with a chemical called
nitroglycerin, a dangerous material that exploded even when just
being handled. He tried many ways to make nitroglycerin safe
to use and eventually developed a safe powder which he called
dynamite. He wanted dynamite to be used for peaceful activities
like mining and construction but eventually it was also used
in war. When he died, he left all his money in a fund for prizes
to be awarded to people from science and literature who help
mankind, including an award for peacemakers.
Link to activities for older students.
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