Why do geysers erupt lesson Montana geography lesson Earth Science lesson 3rd 5th 7th

How Geysers Erupt

by

in

We are studying Montana Wyoming, and so, of course, that means we need to learn about Yellowstone National Park, Old Faithful, and how geysers erupt. Which means I needed to buy some mentos. Stick around to find out how geysers erupt in this great science lesson AND geography lesson.

Why do geysers erupt lesson Montana geography lesson Earth Science lesson

(there are affiliate links in here)

Supplies for our how geysers erupt lesson

Montana printable (in the subscriber library, join my newsletter and get access to hundreds of printables), sodas (2 liters bottles are impressive, but I split our bottle into several, this was a bad decision), Mentos, and if you want Mentos dispenser (handy to get the amazing reaction, and the one I linked to also has the Mentos, but it’s always fun to have more on hand to keep trying again)

Why do geysers erupt lesson Montana geography lesson Earth Science lesson 3rd 5th 7th

A bit of science to explain how geysers erupt

Before teaching this lesson, I didn’t know geysers were mainly in four locations, and over half of the world’s geysers are in Yellowstone National Park.

That is fascinating to me.

Geysers erupt because of pressure and heat underground. They’re like a rebalancing of the pressure underground.

That’s why we can’t really predict when most of them erupt. The geyser mentioned in the video only erupts like every 50 years.

That’s what makes Old Faithful over in Yellowstone so interesting. It erupts ALL THE TIME. I remember traveling to Yellowstone on a family vacation and being amazed to see it erupt.

Learning how geysers erupt as we study Old Faithful

With all of that in mind, when we learned about Yellowstone, I knew it was finally time to try the Diet Coke and Mentos science experiment as a great demonstration of a geyser.

Demonstrating how geysers erupt

Full disclosure, when we attempted to show how geysers erupt, ours didn’t work. I should say, it did erupt, but we didn’t get the big explosion you expect to see. We did a lot of problem-solving to figure out why.

This is what is supposed to happen.

 

 
 
 
 
 
View this post on Instagram
 
 
 
 
 
 
 
 
 

 

Creating our homemade #oldfaithful with the classic #mentosdietcoke experiment

A post shared by Ticia (@ticiam) on

This is what happened with ours.

learning how geysers erupt with diet coke and mentos

We talked over reasons our experiment might not have worked, and these are the reasons we came up with:

  1. Pouring the Diet Coke into the smaller bottles possibly released too much carbon dioxide.
  2. We did not put all of the Mentos in all at once, but they got added in slowly bit by bit.
  3. The wider mouth of the Gatorade bottles probably decreased the pressure a little bit.

After the failure with Diet Coke, the kids had to find out if this would work with other sodas. At this point, our experiment had changed from how geysers work to “what sodas cause reactions with Mentos?”

You know what we discovered?

They all worked. It’s just a difference in how much of a mess it is and how sticky it is afterward. That is why we were outside, we finished up and hosed down the driveway.

after learning how geysers erupt they tried drinking the soda

Then for some strange reason, they all decided to try drinking the sodas they’d put the Mentos in. That sounds like it would taste awful.

how geysers erupt printable
Giant logo because I accidentally got her notebook with her name.

Afterward, we headed in and wrote what we learned, and how geysers work down.

More Geography related Science Ideas

I know I have more lessons, but these were the three I came up with quickly.


Comments

2 responses to “How Geysers Erupt”

  1. I would think it did not work for the first reason – that you let most of CO2 out while pouring soda from one bottle to another. But this one is always such fun regardless of the age 🙂

  2. Sodas with mentos does sound horrible.

    Geysers are fascinating.

Leave a Reply

Your email address will not be published. Required fields are marked *