How fun is this Erupting Pumpkin Activity?! This is a great science activity for kids any time during the fall season, but especially on Halloween!
I first learned about this science activity a few years ago at one of my daughter’s forest school sessions during the week of Halloween. The kids and I alike were totally wowed by it and we all took turns oohing and awing as the pumpkin began erupting and oozing foam all over the place. The kids especially liked it because they got to take turns adding the secret ingredient that makes all the spooky foam. Keep reading to find out how you can help your kids with this fun science activity too!
What you need for this Erupting Pumpkin Activity
- Pumpkin. A real or fake pumpkin will work, as long as it has a hollowed out cavity. We opted for the real one though! It’s fall, so pumpkins are easy to find, plus scraping the innards out of pumpkins may be my kids’s all-time favorite fall activity. You could choose a big pumpkin, or tiny, or lumpy, or smooth, or any kind your heart desires!
- Baking soda. This is a base and necessary for the reaction that causes the bubbly foam.
- Vinegar. This is an acid, and also necessary for the reaction.
- Dish soap. This is optional, but helps it foam up just that much more.
- Water. You’ll use warm water in the cavity of your pumpkin as the main liquid.
Erupting Pumpkin AcTIvity Step-by-Step
- Prepare your pumpkin. First, you’ll need to pick out a pumpkin and get it ready. Clean out the seeds and the rest of the innards to create a hollow cavity. You could carve a face or a design into your pumpkin, but we decided to leave ours whole.
- Combine ingredients. Inside the cavity of your hollowed out pumpkin, add warm water until almost full. Then add 4-5 drops of dish soap (this just helps it bubble up even more). Dump in about 1/3 cup of baking soda.
- Create the eruption. When you are ready for your pumpkin to erupt, add 1/2 cup of vinegar and look out! Watch it instantly foam up and totally delight your kids.
- And repeat. Add more baking soda, then more vinegar over and over again to keep the fun going! Doing this activity over and over again entertained my kids for at least an hour.
The science behind this Erupting Pumpkin Activity
- As you’re doing this activity with your kids, it’s a great time to talk about the scientific end of things. What they see is an exciting eruption of icky oozing foam, but let’s talk about what’s really happening…
- When a base, like baking soda, is combined with an acid, like vinegar, a chemical reaction takes place. The hydrogen ions in the vinegar react with the sodium and bicarbonate ions in the baking soda. It produces a gas called carbon dioxide which is what makes the liquid bubble and fizz and foam up.
- For more scientific information and ideas for more foamy experiments check out Carrots are Orange’s post.
- Regardless of the age of your kids, they will benefit from a science experiment like this. It’s fun, easy, safe, and educational!