Science Projects in an Hour

Many science experiments need a large amount of time to perform and may not be conducive to the classroom. But there are a number of one-hour experiments you can run. These experiments will allow you to teach the students the basics, such as density, buoyancy, chemical reaction and water expansion.

Buoyancy

Teach buoyancy, or how certain objects float, in one hour with a 20-gallon tank, a glass, different types of sodas in unopened cans, eggs and salt. For the first part of the experiment, fill the tank 3/4 of the way full with normal tap water, about room temperature. Place the cans of soda in the water. Which ones float? Which ones sink? How does regular soda differ from diet? The difference between what floats and sinks depends on what is dissolved in the soda. For example, regular soda uses sugar while diet uses artificial sweeteners. Which type is more dense?

Next fill the glass with water and carefully place an egg in it. Does it float or sink? Experiment by placing a teaspoon of sugar or salt in the glass one at a time. This changes the density of the water, and will allow you to talk about how density affects buoyancy.

Diet Coke and Mentos

Use Coke, Diet Coke and Mentos to talk about chemical reactions and pressure with the students. You'll need one Coke bottle of any size, at least two different-sized Diet Doke bottles and a roll of Mentos. Drop a Mentos into the Coke bottle first. Does it fizz? Then drop a Mentos into the larger Diet Coke bottle. Does it fizz more or less than the Coke bottle? This is a good place to talk about how the chemicals in the Mentos react with the chemicals in the Coke, creating a chemical reaction. Next drop a Mentos into the smaller Diet Coke bottle and screw the cap on quickly. It should expand or explode. Be careful. Even if only the cap explodes it could be dangerous. Ensure everyone, including yourself, is at least 20 feet back after dropping in the Mentos and securing the cap. This part of the experiment allows you to talk about how the chemical reaction releases gases, which create pressure. If you have extra bottles on hand you can experiment with what happens if you drop more than one Mentos into a bottle at a time.

Paper Towel Project

This paper towel project is a great way to teach students how to record results on their own. You'll need at least three different paper towel brands and a half, three-quarter and one-cup measuring cup. Fill the half cup with water. Use each of the paper towels to soak up as much of the water as possible. Record your results. Next fill up the three-quarter cup with water and repeat the experiment. Did any paper towels soak up all of the water? Record your results. Fill up the one-cup with water. Repeat the experiment. Did any paper towels soak up all the water? What happened to the towels that didn't soak up the water? Record your results, then make a guess as to why the paper towels reacted differently. These guesses can take into account the thickness of the towels, the materials used to make the towels or the density of the water being soaked up. For example, you might guess that the towels would soak up less salt water -- if you had used it instead -- than tap water because salt water is denser.

Bursting Pipe

This experiment examines the properties of water and ice, and how the same substance can change at different temperatures. You'll need a pipe elbow, two end caps, a bucket of water and liquid nitrogen. If you don't have access to liquid nitrogen you can use a freezer, but it will take longer to enact the experiment. Submerge the pipe elbow in the bucket of water. Seal the elbow with the end caps once it is completely full of water and has no air pockets. Ensure that the pipe cannot leak. Take it outside and spray it with liquid nitrogen. Be careful when you do this. You should wear protective gear, including gloves and goggles. Ensure that anyone watching is standing 10-20 feet back. When the water freezes the elbow will crack and likely explode. You can use this experiment to talk about how water expands when it freezes. What implications does this have for freezing water in the home, such as lawn pipes?