3 Science Experiments that Are Guaranteed Hits at Science Fairs

Here are 3 simple but fun science experiments that are guaranteed hits at science fairs: the backyard rocket launcher, the egg squeezer, and how to produce carbon dioxide.

Looking for awesome science fair projects that will leave other kids goggle eyed? You can, with just a few materials that are easily available at home.

Backyard Rocket Launcher

You’ll need a Styrofoam plate; a toilet paper tube; marker pens; tape; a white camera film canister; and vinegar and baking soda, or Alka-Seltzer tablets. Use the markers to make your own design on the toilet paper tube. This will be your rocket launcher. Tape the rocket launcher to the center of the Styrofoam plate.

Then make your very own rocket fuel by putting 1 tablespoon of vinegar in the film canister. Hold it near the launcher and add ½ teaspoon of baking soda. Quickly snap on the lid and drop the canister into the launcher, lid side down. Alternatively, put 1 tablespoon of water into the canister then add half an Alka-Seltzer tablet and quickly snap on the lid. Drop into the launcher, lid side down, then stand back! The rocket will launch in 10-20 seconds. (If the rocket doesn’t launch, wait at least a minute before checking.)

The egg squeezer

This experiment will show the principle that heat causes most solids and liquids to expand, and cooling causes them to contract. You will need a peeled, hard-boiled egg; a long-necked bottle with opening that is slightly smaller than the egg; and three matches.

Place the long-necked bottle on your kitchen table (or any table free from flammable debris). Light 3 matches and drop them all at once (not one at a time) into the bottle. Quickly put an egg on top of the bottle opening. The egg will be sucked into the bottle.

The lighted matches heated the air, causing it to expand. When the matches are extinguished, the air contracts as it cools. This lowers the pressure inside the bottle than on the outside. A lower pressure is created within the bottle, than on the outside. The pressure outside the bottle causes the egg to get sucked into the bottle.

How to produce carbon dioxide

This simple experiment shows that mixing an acid and a base triggers a chemical reaction that releases carbon dioxide. You will need a clear plastic or glass container; water; vinegar; baking soda; food coloring; and raisins or cereals.

Fill the container almost to the brim with 3 parts water and one part vinegar. Be sure to leave some room at the top of the container. Slowly add one teaspoon of baking soda. Putting the baking soda all at once and too quickly will make the liquids bubble over the top. When the bubbles settle down, slowly add a second teaspoon of baking soda. When the bubbles settle, add a few drops of food coloring. Now comes the fun part. Find some items, like raisins, rice, or cereal. Drop in a few of the first item. They will sink to the bottom, but after a few minutes they will rise to the surface, then sink again. Try the rice, and watch it dance! If the movement seems to be slowing down, add another teaspoon of baking soda.

What has happened? The vinegar is an acid and the baking soda is a base. When you combine them, a chemical reaction produces carbon dioxide. The carbon dioxide bubbles build up on the surface of the object. When enough bubbles attach to it, the object floats to the surface and releases the gas. Then it sinks back to the bottom to start the process again.