Molecules, molecules, molecules!
Initial Publication Date: September 22, 2008
Summary
Water is full of invisible holes. That's because the invisible holes are moving all the time and leaving invisible spaces in between. You can prove that the holes exist and are moving.
CollapseLearning Goals
The hypothesis will be stated and then tested. We will also measure, compute and prove a theory that matter is made up of tiny particles called molecules. Also that these tiny particles are always moving and are separate entities.
Context for Use
3rd grade, classroom or lab setting,
1 cup water in a glass 2 cup measure
1 cup alcohol
food coloring
1 cup water in a glass 2 cup measure
1 cup alcohol
food coloring
Description and Teaching Materials
1. Measure very carefully. You must have exactly 1 cup or water and 1 cup of alcohol.
2. Pour the rubbing alcohol into the cup of water.
3. Now measure again. You'll find you have less than 2 cups. This is one case where 1+1 does not equal 2.
Why? Rubbing alcohol molecules filled the water molecules. The shape of the alcohol molecules let them slide right in between the water molecules.
Another quick experiment would be used to prove that these "invisible" molecules are always moving. Put a little bit of food coloring into water and notice the color starts moving around the liquid, how? The molecules are moving all the time and are "stirring" the water. Another quick experiment would be used to prove that these "invisible" molecules are always moving. Put a little bit of food coloring into water and notice the color starts moving around the liquid, how? The molecules are moving all the time and are "stirring" the water.
2. Pour the rubbing alcohol into the cup of water.
3. Now measure again. You'll find you have less than 2 cups. This is one case where 1+1 does not equal 2.
Why? Rubbing alcohol molecules filled the water molecules. The shape of the alcohol molecules let them slide right in between the water molecules.
Another quick experiment would be used to prove that these "invisible" molecules are always moving. Put a little bit of food coloring into water and notice the color starts moving around the liquid, how? The molecules are moving all the time and are "stirring" the water. Another quick experiment would be used to prove that these "invisible" molecules are always moving. Put a little bit of food coloring into water and notice the color starts moving around the liquid, how? The molecules are moving all the time and are "stirring" the water.
Teaching Notes and Tips
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Assessment
I would ask the kids to record the data and also to record their opinions as to why they think that the 1 cup water plus 1 cup of alcohol do not equal 2 cups.
Standards
NATURE OF
SCIENCE
View
The student will understand
the use of science as a tool
to examine the natural
world.
1. The student will explore the use of science as a tool that can help
investigate and answer questions about the environment.
NATURE OF
SCIENCE
B. Scientific
Inquiry
The student will understand
the nature of scientific
investigations.
1. The student will ask questions about the natural world that can be
investigated scientifically.
SCIENCE
View
The student will understand
the use of science as a tool
to examine the natural
world.
1. The student will explore the use of science as a tool that can help
investigate and answer questions about the environment.
NATURE OF
SCIENCE
B. Scientific
Inquiry
The student will understand
the nature of scientific
investigations.
1. The student will ask questions about the natural world that can be
investigated scientifically.