Christmas Science Experiments

Cranberries and marshmallows seem to always find their way into our kitchen this time of year, so why not put them to use in other, fun ways?! Check out some of the fun experiments our family does to better understand carbon dioxide and buoyancy.

Most kids have some knowledge of carbon dioxide bubbles in carbonated drinks. What happens to small, dense objects when you put them into a carbonated beverage? For this experiment you’ll need a clear carbonated soda (or we used sparkling water). 

And you will need dried cranberries.

Place the cranberries into the soda. The cranberries sink like we would expect because they are more dense than liquid, but watch what happens!


The carbon dioxide bubbles stick to the cranberries and carry them to the top! When the bubbles pop the cranberries sink back to the bottom.

This is a fun experiment to do because the cranberries will keep moving! When they slow down agitate the glass a bit to activate some more bubbles.

After the cranberries see what else you can get the carbon dioxide bubbles to carry. Maybe dried popcorn kernels, raisins or other holiday foods you might have around the house!

For this next experiment you’ll need marshmallows (any size) and a glass or two of water. Ask your kids if marshmallows sink or float.

Place a marshmallow into the water.

Talk about why they float and study the concept of buoyancy.

Marshmallows have LOTS of air inside so what can you do to remove that air? Can you push it down, poke holes in it…

You can use the same glass or have several glasses and see who can come up with the best way to get the air out of the marshmallow and make it sink. Try them all out!

We squished a marshmallow between two pieces of waxed paper to remove enough air to finally get one to sink!

The water will get cloudy from the marshmallows so have some extra water on hand to replace it if it’s getting hard to see. Have fun and enjoy exploring some scientific concepts through the experiments!  Want more experiments and tips?  Follow Allison’s blog and facebook page to get more information, experiments, and encouragement. Looking for more homeschool idea’s and tips? Follow our blog by entering your information at the top of the page and never miss a post!