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Pennsbury School District, Edgewood Elementary
School Diane DiMaggio and her 3rd grade students don't need an official lab filled with test tubes to explore chemistry. They can do it right in their small detached classroom at Edgewood Elementary School in the Pennsbury School District. With help from STC's Chemical Tests kit, Diane has introduced her young chemists to basic concepts about matter and its changes. The class has been actively engaged in describing properties of objects and substances, conducting simple tests, and systematically recording observations as they work to solve the mystery of five unknown solids—common household substances identified only by colored sticker dots.
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Based on their early observations, teams of students
have made predictions about what each of the unknowns
might be. They have also experimented by combining
each unknown solid with a liquid (water); observed
what happened when the substances interacted; and
poured their mixtures through filters into Petri
dishes.
Diane began the lesson by compiling the group's
observations, asking whether or not each unknown dissolved,
if the liquid was cloudy or clear, and if the mixture was a
solution or a suspension, or both. Students were able to
refer to their own direct experience as they used this
scientific terminology.
All agreed that the red sample had dissolved in the water and that the clear result could be called a solution. The green unknown made the water cloudy and murky. It "stayed in blobs" so was recognized as a suspension. And as they continued to add small amounts of the yellow and blue to the water, mixtures reached a point where no more could dissolve, leaving the water clear but with some unknown still visible on the bottom of the cup. One sample left many students feeling "iffy"—the mixture was cloudy and milky, but so watery some felt the unknown had "kind of dissolved." They will repeat the test the next day to come to a more satisfactory conclusion. |
The next step was for students to look closely at
solids remaining on the filter paper and evaporation
dishes used in their previous test. The Chemical
Tests unit is materials intensive, but cardboard lab
trays and colored stickers help to keep things
organized. Organization also makes the distribution
of materials and movement around the room go
smoothly: Diane reminds students that each team
member has a particular task—number ones get the
"science bucket," twos clean up, and threes get the
tray.
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Following the basic direction "Whatever you see,
write down, " students begin to record their
observations. Diane also suggests drawing pictures
as another way of representing results.
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As the groups go to work, students share and compare
their observations: "I saw something glisten,"
"sticky crystals," and "It looks like broken pieces
of plastic, or sugar stuck together."
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Although Diane reminds students that that tasting is
NOT a good idea, using other senses can add to visual
observations: "This smells like baking soda."
Another unknown was described as having a sweet
scent, or no scent at all. |
Time is always a concern when doing science
investigations, but Diane has found a way to
coordinate with the special education schedule and
have all students participate. Rather than having
every team do tests on all five unknowns, each group
works on three. All samples are examined, and the
class as a whole has data to solve the mystery.
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| Looking forward to the following day, Diane explained
that the class would again pool their observations to
discover which mixtures could be separated by filtration and
which by evaporation. As they conduct further tests during
the rest of the unit, students will continue to practice
their investigation skills and apply their knowledge to
solve new mysteries.
Many thanks to Diane and students for inviting us into their laboratory! |
