Pumpkin Carving and Science Fun: Dancing Seeds

Pumpkin Carving and Science Fun: Dancing Seeds
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It is that time of year again, everything pumpkin. The first day of fall is exciting for the thoughts of cooler weather around the corner and all those fun-filled fall activities. We decided to start out our fall with some pumpkin carving! Who doesn’t love to carve pumpkins?

Well my son is not too fond of gutting pumpkins. I think it’s a texture thing. It does get pretty slimy and stringy. Now that you will have all your kids sitting around the pumpkin during the carving, why not throw in some science fun? I think it is the perfect time! In this science activity, we will be having a dance off! Yep, you heard me right. There will be a dance off between a few pumpkin seeds collected and some raisins.

Items Needed:

1 pumpkin needing to be carved

1 bottle of carbonated water

3-4 raisins

Plastic cup to host the dance party

Science Activity Steps

The pumpkin carving should be done by an adult. I am not even comfortable with myself cutting up a pumpkin 😉 My daughter decided for a ‘vampire’ look for our pumpkin. Thankfully it wasn’t anything too difficult. She can come up with some pretty creative ideas for a 6 year old haha! As you are cleaning out the pumpkin, set a side 3-4 pumpkin seeds.

Once you have collected your pumpkin seeds, you can start setting up the dance party. Fill the plastic cup about 3/4 full with the carbonated water. Then add your pumpkin seeds one at a time. Tell your kids to observe their behavior in the cup. Do they sink? Are they moving around?

Next, add in the raisins one at a time. Observe their behavior. Do they sink? Are they moving around? It may take a minute or so for the ‘dancing’ to begin. Your kids should be able to see the raisins sink to the bottom and the pumpkin seeds float to the top. The raisins will begin to ‘dance’ by bouncing up and down in the cup. The only dancing you will see from the pumpkin seeds is a few bounces and a little side-to-side dancing (pretty much me at a dance party!)

Why did they behave this way?

The pumpkin seeds are less dense than the water, therefore they float. The raisins are more dense, so they will sink. If you are working with littles who don’t quite get the concept of ‘dense’, I usually just say that one is ‘heavier’ and one is ‘lighter’. Now for the dancing part. Since the pumpkin seeds are floating, they are not affected by the carbon dioxide bubbles. The only reaction they are having is the small bouncing or moving from the bubbles popping underneath them. The raisins are a different story. As the carbon dioxide bubbles surround the raisins, they make the raisins lighter for that brief amount of time until they reach the surface and the bubbles pop. Then the raisins become more dense, ‘heavier’, and sink back to the bottom.


Who knew pumpkin carving, let alone the seeds, could be apart of something ‘sciency’?! Happy Fall and Halloween!

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