Grow the Grinch’s Heart Science Experiment

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One of the best parts of How the Grinch Stole Christmas is this scene: the Grinch is straining as he holds the sleigh balancing precariously on a mountaintop. He hears singing and then pop, pop, pop, his heart fills with joy.

I love watching How the Grinch Stole Christmas every year and I was dying to do an activity based on this favorite movie. So, we took a classic science experiment, gave it a Christmas-sy twist to get this fun Grow the Grinch’s Heart Science Experiment.

Try some Christmas science with this fun Grow the Grinch's heart science experiment. It's a STEM activity with a Christmas twist.

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Supplies Needed:

Green balloon
Red Sharpie
Empty water bottle
White vinegar
Baking Soda

Before you begin your project, you’ll want to make the Grinch’s small heart.

Take a green balloon and use your red Sharpie to draw a simple heart on the balloon.

Give it a minute to dry before you begin your grow the Grinch’s heart science experiment.

Grow the Grinch’s Heart Science Experiment.

For the first step in your experiment, add some vinegar to your empty water bottle. I filled it up to about the second groove from the bottom. Eyeball it. You don’t need to be exact.

Attach your balloon to the bottom of your funnel (like the picture above). Fill the balloon with about two to three spoonfuls of baking soda. You may need to shake it a bit to get all the baking soda into the balloon.

Remove your balloon from the funnel.

Carefully, without dumping any baking soda into your bottle, attach the balloon to the top of the water bottle, like you see illustrated in the photo above.

You’re all set up! Get ready to grow the Grinch’s heart.

Grow the Grinch's heart with this fun Christmas science activity based on this favorite book. It's a STEM activity with a Christmas twist.

Lift the balloon up and shake the baking soda into the bottle. Your balloon will start inflating immediately.

You can let go once the balloon starts filling up and watch the Grinch’s heart grow three sizes (or more).

Why did the Grinch’s heart grow?

The combination of baking soda and vinegar formed a gas called carbon dioxide, which filled your balloon.

This is the same gas that forms the bubbles in your favorite carbonated drink.

Have you watched How the Grinch Stole Christmas yet this year?

When you do, add a little extra fun when you do this grow the Grinch’s heart science experiment.

You may also enjoy one of these winter science activities:

Hot Chocolate Science : How does temperature affect the rate that hot chocolate dissolves?

Snow Science Prediction and Observation: Make some predictions about how quickly snow melts in different conditions.

Hockey Science: Experiment with friction when you do this fun science project inspired by the game of ice hockey.

Christmas Magic Milk Science at Little Bins for Little Hands: Try another classic experiment with a Christmas twist.

My must-have resources for STEM fun:

If you love to have STEM projects on hand, but don’t always have time to prep, why not give a subscription box a chance. I love Green Kid Crafts for this reason. The boxes are packed full of projects that are fun and inviting. You can choose to get a subscription or a one-off box based off of a specific theme.

Here are some of our favorites (you can purchase and  find out more at each link):

Get a monthly subscription.

Kitchen Science Box

Physics Box

Find all their fun STEM boxes here.

Are you looking for more kids activities?

Join our fun Facebook community, Creative Family Fun for Busy Families, for daily activities that are great for kids and families. We’ll chat, share, and have fun. It’s a safe and private place to share ideas for family and kids activities.

I’d love for you to join me! Just click the link below, request to join, and answer the questions (they’re easy, I promise). Come join the fun! Join the Creative Family Fun for Busy Families community here.

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Terri is a writer and mom of two elementary-aged girls. She has a passion for learning and is always looking for ways to make learning fun. You can find her here writing about fun learning activities, art, craft, and family fun ideas.

Latest posts by Terri Thompson (see all)

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