From Lawrence Hall of Science
The GEMS Oobleck guide:
http://lhsgems.org/GEM200.html
Communicating Science Course:
http://www.lawrencehallofscience.org/comsci/
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For the Oobleck Lab Investigation 1. Preparation and Mixing. If possible, start mixing the
Oobleck about two hours before class. It’s possible to
mix the Oobleck shortly before class, but you can make
any necessary adjustments more easily if you allow
yourself more time. In any case, allow at least 45
minutes to prepare the Oobleck, and to set up the work
stations and the equipment station for the lab
investigation.
. 2.
Prepare the Oobleck. The proportions used here—4
boxes cornstarch, 6 3/4 cups (1600 ml) water, and
about 15 drops of food coloring—will make enough for
six teams of students to have about 1 1/2 cups of
Oobleck each. Keep an additional box of cornstarch on
the side to thicken the mixture in case it becomes too
soupy. a. To prepare the Oobleck, add 15 drops of green
food coloring to 6 3/4 cups (1 liter or 600 ml) of
water in a dishtub or large mixing bowl. Slowly
sprinkle in the contents of four boxes of
cornstarch. Swirl and tip the bowl to level the
contents.
Note: Food coloring should not be added after the cornstarch,
because at that stage it is difficult to mix evenly. Also, adding more
than the recommended amount of food coloring may cause Oobleck
to temporarily stain hands.
b. Mix the Oobleck with your hands (not a spoon) to
ensure an even consistency. Do not try to push
through the Oobleck mixture as if mixing batter, as
that will prove very difficult. Instead, keep “lifting”
the Oobleck from the bottom of the bowl to the top
by slipping your fingers under it, until an even
consistency is reached.
c. A few minutes before you plan to start the activity,
mix one more time if water has separated.
d. Pour about 1 1/2 cups (350 ml) of Oobleck into each
team’s bowl. Then put the bowls aside until after you
introduce the activity .
Oobleck Laboratory Investigations
1. Set stage for Oobleck explorations. Tell participants to
imagine they are on a space ship far out in space and have
sent a space probe down to a recently discovered moon
within our Solar System. The moon is covered with what
appear to be large green oceans, and three probes have been
sent down. Contact with the first probe was lost, and what
happened to it is unknown. The second probe is stuck on the
surface, but the third probe managed to return with a
sample of the ocean material.
2. Participants as scientists. Ask the participants to imagine
they are a group of scientists in a laboratory on board a
spaceship orbiting the newly discovered moon. It is their
task to investigate the properties of the sample and collect
evidence about the substance.
3. Explain Oobleck is safe to handle. Show participants the
bowls of Oobleck, but don’t distribute them yet. Mention
that preliminary studies have shown that Oobleck is safe to
handle. Add that a team of chemists is trying to find out its
exact composition, and their results will be revealed when
their research is completed.
4. Introduce materials and begin investigations. Explain
that their job is to investigate the properties of Oobleck.
Hold up a pencil (or another convenient observable object)
and ask them, “What is a property of this pencil?” As they
offer examples, make sure they understand that a property is
anything you can observe directly about an object. Point out
where they can collect the assorted test items, and the
newspapers for covering their tables. Distribute a bowl of
Oobleck to each table group and have them begin
investigating.
5. Distribute paper for recording properties. After
participants have investigated Oobleck for a few minutes
and discovered some of its unexpected properties, give each
group a large sheet of paper and a felt-tipped marker to start
recording the properties. (If needed, help participants by
circulating and asking questions such as, “How does
Oobleck behave when you press on it?” “When does
Oobleck behave like a solid?” “When does Oobleck behave
like a liquid?”)
6. Suggest participants test their ideas. Encourage them to
resolve disagreements by performing experiments or
discussing ways to describe a property so everyone on the
team agrees.
7. Indicate properties related to solid or liquid
characteristics. Ask each lab group to put a star on their list
next to the property of Oobleck they think is most important
in explaining under what circumstances Oobleck acts as a
solid or as a liquid.
Oobleck: Scientific Convention
1. Introduce context for scientific conventions. Remind
participants that professional scientists in most fields and
disciplines travel all over the world to attend meetings called
scientific conventions. The topics might be “Heart Disease,” or
“The Planet Mars” or “Earthquake Prediction.”
2. Explain purpose of convention. Point out that during a
convention, scientists listen to each other’s experimental
results and research findings and critically discuss them. The
goal of the convention is not to prove each other right or
wrong, but to arrive at the most accurate scientific
understanding and to state it as clearly and completely as
possible.
Introduce Spacecraft Design Activity
1. Discuss the importance of applying findings. Mention to
participants that in the Oobleck: What Do Scientists Do? GEMS
unit, there are two other activities. One of these is another
very important part of what scientists (and engineers) do,
and that is to apply their findings. In a similar way, in
education one key criteria for evaluating or assessing
student learning is whether or not students can apply what
they’ve learned in a different context.
2. Describe spacecraft design assignment. In the Oobleck
unit, students are asked to design a spacecraft that would be
able to land on the ocean of Oobleck, explore the whole
moon, and take off again, with all passengers aboard.
3. Explain how some students have used what they’ve
learned about Oobleck. Tell participants that some
elementary school students have come up with very creative
ideas, such as flying machines with thousands of little feet
that continuously press on the Oobleck so it stays solid.
Others have suggested a hovercraft concept, a craft with
Oobleck dryers, or a landing platform with a detachable
return shuttle.