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Simple STEM Science Experiments for Ages 3 and Up-Part 1

Updated: Jan 18, 2021

Fun Satisfying STEM Learning for Kids (That Won't Disappoint)

Cheers to 2021! 2020 was extremely difficult for all of us, including our children. With all the changes and most of our kids not being in traditional school, finding learning opportunities outside of the typical school setting to help our kids stay ahead of the curve has been on many of our minds.

So here are some easy but extremely fun (for kids and adults alike) science experiments you can do with your kids as young as 3 years old for some at-home, learning fun.

In this post, I will give you instructions for: DIET COKE & MENTOS (Mini/Starter and Larger Scale versions), TORNADO IN A BOTTLE, and PAPER MACHE VOLCANIC ERUPTION.

In my next STEM post, I will give you instructions on 3 more fun but easy science experiments. EXPLODE A BAG, THE DISAPPEARING TEST TUBE, and RAINBOW IN A GLASS/TEST TUBE.

Stay tuned or subscribe to make sure you're notified. Now let's have some science fun!


What You Will Need (Mini/Starter Version)

- 20 oz Diet Coke bottle

- 1 Mentos (original mint flavor)


  1. Things will get a little messy. So, take your experiment outside or you can use a large wide container on a flat surface for the mini/starter version.

  2. Open your bottle of Diet Coke.

  3. Drop the Mentos in the bottle and see your reaction immediately!

  4. Wasn't that cool? Now if you're ready, you can graduate to the large scale version below.

What You Will Need (Larger Scale Version)

- 2 Liter Diet Coke bottle

- 1 whole roll of Mentos (original mint flavor)

- Geyser tube ($5 or $6 on Amazon)

- Safety goggles


  1. This will get even messier. So, make sure to take this experiment outside.

  2. Put on your safety goggles.

  3. Open your roll of Mentos and insert them all into the geyser tube.

  4. Open the bottle of Diet Coke and attach the geyser tube.

  5. Stand back and pull the release string on the geyser tube to release the Mentos.

  6. Enjoy the eruption!

  7. Save the Coke bottles for Experiment 2 below.


What You Will Need

- Two empty 1-2 Liter bottles

- Water

- A vortex connector, $6 or less on Amazon (or you can substitute a metal washer and duct tape)

- Food coloring, color of your choice OR dish soap (optional)


  1. Cut the plastic ring off of the necks of your bottles.

  2. Fill one of the bottles 3/4 full with water.

  3. Screw on the vortex connector to the bottle full of water (or place the metal washer on top of the bottle).

  4. Then screw on the empty bottle so that the empty bottle is on top and the bottle with water is on bottom. (If you are using a washer, have another person hold the two bottles together and use duct tape to secure them together.)

  5. Once everything is secure and there are no leaks, flip your bottles and quickly rotate clockwise to create the tornado effect.

  6. Try the experiment again after adding a few drops of food coloring or dish soap and watch how it creates a different visual effect. Pretty cool, huh!


What You Will Need (Making Your Volcano)

- Instant paper mache (CelluClay or similar brand), 1 pound, $12-$14 on Amazon

- Water

- Wax paper

- Safety goggles

- Paint (optional)


  1. Put on your safety goggles.

  2. Pour the instant paper mache into a large bowl (be careful not to breathe in or let your child breathe in the dust).

  3. Pour 4 cups of water into bowl and mix with your hands or a wooden spoon until all the paper mache is wet and the consistency is like cookie dough (thick but moldable).

  4. Dump your mixture onto your wax paper.

  5. Have fun shaping your paper mache into a volcano.

  6. Use your fingers to make a hole in the top of your volcano about 2 inches deep (don't make it too deep or your eruption will not come all the way to the top of your volcano).

  7. Set your volcano on top of the wax paper to dry in an area that gets sunlight. Your volcano will take 2-3 days to dry.

  8. Optional: Once dry, paint your volcano as desired. Paint little trees or dinosaurs at the bottom of your volcano or use some toys you may have to create a more realistic scene (and because it's fun!)

  9. Set your volcano to dry again for at least 24 hours.

What You Will Need (Making Your Lava)

- Baking soda

- White distilled vinegar

- Dish soap

- 1-2 small cups

- Red food coloring (or any other color you want)

- Wide flat container (optional but helps with mess)


  1. Place your volcano inside of a wide container (like a large bowl, storage container, or serving tray).

  2. Put on your safety goggles.

  3. Place 1 tbsp of warm water, 1 tbsp baking soda, and a few drops of dish soap into a cup and stir.

  4. Pour the mixture into the top of your volcano.

  5. Wash and dry your cup or get a clean cup.

  6. Pour 1/2 cup vinegar into your cup, then add a few drops of (red or other color) food coloring and mix. Add a few more drops of food coloring if you want a richer colored lava.

  7. Then, quickly pour the vinegar into the top of your volcano, step back, and watch your volcano erupt!

I hope you and your child had a blast with those experiments and your child is on their way to realizing how fun science can be!

In my next STEM post (Part 2), I will give you instructions on 3 more fun but easy science experiments. EXPLODE A BAG, THE DISAPPEARING TEST TUBE, and RAINBOW IN A GLASS/TEST TUBE.

Subscribe to make sure you're notified of more posts like this!

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1 Comment

Fantah Hyson
Fantah Hyson
Jan 04, 2021

These look like fun projects. I will attempt them with my 6 year old. Fingers crossed for no disaster!!

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