In the Trenches

Thoughts and Ideas from a Classroom Teacher

Science Fair

on January 10, 2012

My students’ science fair projects are due tomorrow. What a stressful day! Leading up to the final due date, I tried to do activities with my students that would reinforce the idea that this does not need to be an attempt to solve world hunger. It should be fun, solve a problem and use the scientific method. Last week, we did an experiment to prove that it is possible to complete a science fair project in one hour or less. We had a blast! Here’s how we did it…

Topic: What’s the fastest way to melt an ice cube using only yourself?

Hypothesis: Thinking about what causes ice cubes to melt, what factors need to be considered? The students generated the idea that heat melts ice cubes, and smaller ice cubes melt faster than larger ones. Using this information, each student came up with a plan for melting their own ice cube and recorded it.

Materials: Uniform ice cubes (at least 2 per student), plastic zipper bags (at least 2 per student), a timer, place to record times

We also had a great discussion about constants and variables here. All ice cubes had to be the same size. The bags had to be the same size and brand.

Procedure: Hand out plastic bags. Give each student an ice cube to put directly in their bag. Students should seal their bags. Everyone did a quick seal check by flipping the bag upside down and doing a quick shake. On the “go” signal, everyone should carry out their plan to melt their ice cube. Before we began, we agreed that we would define “melted” as being completely liquid, with no solid pieces left in the bag. As students completed the melting of the ice cube, mark the time it was completely melted. When everyone has finished melting their ice cube, students should analyze the top 5 finishers and the last 5 finishers, noting what their actions had in common. They create a new hypothesis with a new plan to improve their “melt time” based on the new information. Record new trial information.

Results: Write a description of the method of melting and the time it took to melt the ice cube.

Analysis: What do the fastest times have in common? What do the slowest times have in common? What generalizations can you make about your findings ? I won’t go into the results here. I don’t want to give it away. 

Next Time: Students listed different ways they might attempt the same experiment. They also considered variables to change. Some things they came up with included:

What would happen if you used different types of ziploc bags?

Which types/shapes of ice cubes melt faster?

 

 

 

Photo Credit: Ice Cube

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