By Scott Rhodes

It’s no secret that students learn better through hands-on projects, particularly in subjects like science, technology, engineering and math (STEM subjects). For teachers, principals and education leaders, science experiments are a great way to elevate classroom participation and pique student interest in STEM careers and concepts. When students aren’t just listening, but talking and moving, they activate multiple areas of the brain, making it more likely they’ll retain the information.

A little fun in the classroom—and maybe a little mess—never hurt. Take a look at these five science experiments and consider including them in your lesson plans.

## 1) Make Your Own Lava Lamp

Materials:

• 8-16 oz plastic bottle with lid
• Vegetable oil
• Water
• Funnel (optional)
• Food coloring
• Alka-Seltzer tablet (*option to pre-cut tablet before experiment)

Instructions:

1. Fill the plastic bottle halfway with water
2. Fill the remainder of the bottle with vegetable oil
3. Watch as vegetable oil floats on top
4. Add 10-12 drops of food coloring
5. Cut Alka-Seltzer tablet into small pieces (or instruct students to cut) and place one piece into the bottle
6. Watch as it fizzes and creates a lava-lamp effect
7. Continue adding Alka-Seltzer tablets into the bottle to simulate the effect

What’s Happening:

Because oil has a lower density than water, it floats on top of the bottle. The food coloring falls directly through the oil and mixes with the water. Alka-Seltzer tablets react with water and release carbon dioxide gas. Because the food coloring has already dissolved in the water, the Alka-Seltzer tablets create “colored” bubbles, which then rise to the top of the bottle.

What happens when you add oil to the water bottle? Why do you think this happens?

What happens when you add food coloring into the bottle? Why do you think this happens?

What happens when you add more Alka-Seltzer to the bottle? Why do you think this happens?

What will happen when you put the lid on and shake the bottle?

## 2) Roll a Can With Static Electricity

Materials:

• Empty soda can
• Balloon (blown up before experiment)

Instructions:

1. On a flat surface, place the soda can on its side
3. Hover the balloon over the can (be careful not to touch it)
4. Using the balloon, guide the can to move side-to-side

What’s Happening?

By rubbing a balloon on your head you create static electricity, or non-moving electricity. This causes a buildup of electrons on the balloon, in turn giving it the power to attract light objects.

Questions to Ask During the Experiment:

How long or far does the can roll before you need to rub the balloon on your head again?

Does the size of the balloon change the strength? What happened?

Does rubbing the balloon a certain way change the strength? (Back-and-forth or side-to-side)

## 3) Make Coins Jump

Materials:

• Bowl of cold water
• Glass bottle
• Coin (bigger than the bottle opening)

Instructions:

1. Place the bottleneck and the coin in the bowl of cold water (don’t fill the bottle with water, just place it in there to chill).
2. Remove from water; place the coin on the top of the bottle.
3. Wrap your hands around the bottle; watch what happens to the coin.
4. After several seconds, the coin will vibrate and “jump.”

What’s Happening?

Thermal expansion: when something is heated, the matter changes in volume. In this case, the heat from your hands warms the air inside the bottle, which causes the air molecules to expand and force their way out of the bottle.

Why do you think the coin stopped “jumping?”

What do you think would happen if you used colder water? Or had warmer hands?

## 4) Soar with Paper Airplanes

Materials:

• Paper
• Room for “flying” (preferably a gymnasium)
• A long tape measure
• A notebook to record results

Instructions:

1. Create three paper airplanes and label them 1, 2, 3 (for examples, see 10 Paper Airplanes)
2. Practice throwing them to reduce variability in force or angle
3. After a few throws, determine an “official” starting point for the experiment
4. Throw each plane, then measure the distance; record as “Throw 1”
5. Repeat three more times
6. Average the distances for each plane
7. Determine which variation flew the farthest

What’s Happening?

The Law of Aerodynamics states there are four forces of flight: weight, lift, thrust and drag. Adjusting the folding will change how far, high and fast the plane flies.

• Weight – pulls the plane down
• Lift – pulls the plane up
• Thrust – propels the plane forward
• Drag – holds the plan backward

Questions to Ask During the Experiment:

Predict before starting: Which plane do you think will fly the farthest?

After experiment: What impact did the folding (place and number of folds) have on the distance?

Why do you think the plane that traveled the farthest did so?

## 5) Model the Dead Sea

Materials:

• Egg
• Clear drinking glass (choose a deeper size to give the egg enough room to float)
• Water
• Salt
• Measuring spoon (also used for stirring)
• Measuring cup

Instructions:

1. Fill the drinking glass with water, keeping track of how much, and carefully place the egg in it
2. Add 1 tablespoon of salt and stir
3. Notice if the egg is still on the bottom of the glass. If yes, add more salt, keeping track of how much you add.
4. Optional: Calculate the ratio of salt to water needed for the egg to float

What’s Happening?

Density is a measure of how much matter is in a certain space. An object, like an egg, will float or sink depending on the density of the water. A higher ratio of water density to object density will cause an object to float; a lower ratio will cause it to sink. Salt takes up space in the water, which means there is now more matter in the glass than when you started. Because the water is more dense than the egg, the egg will float.

Questions to Ask During the Experiment:

Predict: What happens to objects in salt water? How much salt will the egg need to float?

Why does salt increase density?

What type of objects do you think will float without any salt?

Experimenting in science-related activities throughout a child’s elementary education is key to instilling a love of STEM. Share your favorite science experiments to help inspire students in the classroom and beyond.

For more, see:

Scott Rhodes is the Vice Provost of Enrollment at Florida Polytechnic University. Follow them on Twitter @FLPolyU

Stay in-the-know with all things EdTech and innovations in learning by signing up to receive the weekly Smart Update.