The Marvels of the Molecule

Douglas Xavier Key Douglass Math and Science Academy
543 North Waller
Chicago IL 60644


Grades 5-8.

Describe the concept of the molecule.

Create a model of a water molecule.

Explain molecular theory.

Use phenomenological approach.

Materials Needed:

Water molecule model: Peach, cherries.

No heat demonstration: Handkerchief, small glass, rubber band.

Fire syringe demonstration: Fire syringe, flame paper.

Station #1: Cola bottle, balloon.

Station #2: Baby food jar, Straw, red/blue food coloring, clay.

Station #3: Notebook paper, paper hole punch, small glass, toothpick.

Station #4: Paper cup, toothpick, water.


I will use hands-on experiments so the class will be able to identify
molecules moving or attracting each other. Students will create water and
methane molecule models, demonstrating how they are shaped.
After discussing how molecules are shaped the class will work at four
different stations.
At Station 1 the kids will try to inflate a balloon inside a bottle. The
balloon will not inflate because of air already present in the bottle. If you
would like to expand this experiment, direct the children to try to inflate a
balloon inside a plastic two liter bottle. After they are done trying this,
punch a small hole at the bottom of the small cola bottle and the two liter
bottle. Then try blowing into the balloons. The balloons should inflate
because the air inside the bottles is escaping through the hole in the bottom
allowing the balloons to expand and inflate.
At Station 2 the groups will do an experiment demonstrating the forces of
gravity. In this experiment, the children will lower a straw into clay placed
at the bottom of the jar that has colored water in it. They will quickly turn
the jar upside down, pouring the water out. There should be water left inside
the straw but not the jar. The air inside the straw pushes up on the water when
the jar is inverted and water molecules are pulling from side to side. These
forces are greater than the downward force of gravity; thus the water remains in
the straw.
At Station 3 the group will observe the movement of paper circles that seem
to have a mind of their own. In this experiment the children will fill a cup
3/4 full of water. When the water is calm, they will place a paper circle on
the surface in the center. The paper circle should float to the side of the
cup. After removing the paper, fill the cup to overflowing with water. When
the water is calm, place the paper circle in the center. The paper circle
should remain in the center. Surface water molecules pull on each other, but
they are more attracted to the molecules in the glass. This attraction causes
the water to be pulled toward the glass. The glass that is overfilled with
water does not have the exposed glass sides for the water to be attracted to.
At Station 4 the group will observe separate streams of water forming one
stream when pinched together. In this experiment the children will punch four
holes in a cup. The holes should be as close together as possible in a straight
line 1/4 inch from the bottom of the cup. Fill the cup with water. Take your
thumb and finger and pinch the four streams of water together. There should now
be one stream of water forming.
It is very important to explain to the children that they will have to note
their results from their four experiments in their science notebooks.

Performance Assessment:

Students should be able to define molecule and draw a model of a water
molecule. Students' knowledge of molecules should be greatly enhanced after
performing the four experiments. Oral discussion will follow the experiments
to further develop the concept of molecules.


I would like to thank the many people that helped me with my mini-teaching
lesson. I would especially like to thank my mentor, Barbara Pawela for her help
and support, Ed Guzdziol, Jake Carter, Ed Metzl, and Pat Riley for their many
exciting experiments.

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