Sunday, May 11, 2014

Mentos & Diet Coke

What happens when you add Mentos candy to Diet Coke?
Amazing 20 foot geyser!
How does this happen? Carbon dioxide is pumped into soda and it wants OUT, as you can see/hear anytime you open a new bottle of soda -that hissing sound is the CO2 escaping. A piece of Mentos candy has microscopic pits all over it. These are called nucleation sites - places where CO2bubbles can grab onto. A ton of CObubbles will form all over each Mentos candy as they sink to the bottom (we put in 8 candies) . The bubbles seed more bubbles as they rise & soon there is a raging foam in the bottle - pressure builds & the result is a huge geyser! Almost all of the soda comes shooting out of the bottle! I do this every year with my students & I never get tired of the looks on their faces - priceless! I use this experiment to teach the scientific method: making observations, asking questions, making hypotheses, recording data, making conclusions. 
         Using this tube has made it much easier for me to get out of the way before the geyser erupts:
There are so many questions you can address in this activity/ so many ways to change the variables, here are some of the questions I've investigated with my kids: 
 Does it work with fruit Mentos? (yes) 
Does it work with Sprite? (yes) 
Does it work with soda that has been sealed but left in my science closet for a year? (no!)
 Does it work with Life Savers? (no!) 
I like to have my students write down 2 variables they would like to change and then I choose a couple of the experiments to try each year.

I also use this experiment to teach solids (Mentos), liquid (soda), gas (carbon dioxide)  - fun fun fun & educational too!

Hope you had a wonderful Mother's Day!


  1. I love this! Can you tell me more about the geyser tube? How to use it? Where to buy it? We have Science day this Friday at my school!

    1. Hi Diana, I bought it on Amazon. You load it up with candy, pull the pin when you're ready & all of the candy is released at once into the soda bottle. It gives you a chance to get away from the bottle before it blows! Have fun!!

  2. Sue, I just followed you on Bloglovin, and I wanted to tell you I really appreciate your comment to me on the TPT forums. It's so helpful when sighted people can tell me what I'm doing wrong with my pictures. It's a little hard sometimes, being a blind seller, because I'm not sure what I have to do make things look perfect for both sighted and blind readers of my blog. Can you tell me more about how to make an image pinnable in a blog post? My reader isn't sure about that. Also, would it help with the pinning aspect of things if I make free TPT products instead of offering freebies through Scribd?

    I love your blog, and I'm going to start using these terrific science experiments with my kinders. Science is my favorite subject! :)

    Sharon Dudley, NBCT
    Teaching with Sight

    1. Hi Sharon, I just watched your video on your blog - you're amazing and your students are lucky to have such a caring teacher! I would offer freebies on both Scribd & TpT. When your blog readers go to TpT to download a freebie, they'll hopefully browse your store & maybe even buy a product! Scribd is good for those who do not have a TpT account. I'm going to make a pinnable image for you. I'll make it for your Living/Non-Living graphic organizer so you can see what I mean. I will email it to your gmail account. Have a great weekend! Sue :)


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