Strand: Understanding Matter and Energy

Dancing Raisins

Grade Level: Grade 3

Strand: Understanding Matter and Energy

Topic: Forces Causing Movement

Overall Expectations

Assess the impact of various forces on society and the environment

Demonstrate an understanding of how forces cause movement and changes in movement

Applicable Specific Expectations

2.2 – Investigate forces that cause an object to start moving, stop moving, or change direction

3.2 – Identify different types of forces

3.4 – Explain how forces are exerted through direct contact

Required Materials

Plastic see-through cups

7up/Sprite/Ginger Ale

Raisins

Water

Procedure

Have students identify both the water filled and soda filled cups (they are labeled)

Ask students to hypothesize as to what would happen if we put the raisins into the cup with water

Have students put the raisins in the water/describe what happened

Have students predict what will happen when we put the raisins in the soda

Put raisins in soda and have students hypothesize why they floated to the top and then fell back down to start the process over again

Scientific Explanation

Carbonated water contains dissolved carbon dioxide gas. This gas will collect on the uneven surfaces on the raisins. When enough gas has collected, it will actually lift the raisins to the surface (kind of like little tiny parachutes) where the gas is then released into the air. With the gas now gone, the raisins will sink back to the bottom where the process begins anew.

Note: Carbonated water is produced by adding carbon dioxide gas to water under pressure. The gas makes the water bubble and fizz.

References:

Reeko's Mad Scientist Lab: Dancing Raisins Experiment

Website:

The Ontario Curriculum Grades 1-8: Science and Technology, ISBN 978-1-4249-5661-6

Other Considerations:

This would be a great 'hook' activity for work with force and movement. In grade three, students are not required to know about carbon dioxide or its effects, but by using it in this experiment, it allows students to see how materials in their everyday world have an affect on each other. I think the details of the scientific representations of water(H2O) and carbon dioxide (CO2)may be lost on a grade 3 class, but I think this child-friendly environment is a great entrance into such information. The experiment is a super way to show students that even small raisins can be affected by force – it does not have to be a pulley system or something large.

I used this as a hook in a grade 4 class and they loved the experiment. I believe they benefited from this experiment because the materials were child-friendly and accessible, to most students, outside of the classroom. As well, it was clear to see what was happening to the raisin because the bubbles were very easy to see. Just to make sure that we were all on the same page, I drew a raisin on the board, making sure that there was texture to it. I drew bubbles the coming up and how they caught onto the textured parts of the raisins.

Presenter: Elizabeth Baldwin