More Explorations with Gobstoppers

I’m looking forward to this year’s National Chemistry Week even more than usual.  The 2014 theme “The Sweet Side of Chemistry” offers an opportunity to share the chemistry of candy, a super high-interest topic.

It’s still six months away, but I got a chance for an early taste last month while developing materials for a resource packet on candy to send to American Chemical Society ChemClubs. I included a lab experiment that used Tom Kuntzleman’s post “Fun with M & M’s” as a jumping-off point. In playing around with the Gobstoppers while putting together the experiment, I wondered what might happen if an additional Gobstopper was allowed to dissolve above already-existing layers of color. You can see the setup and results in the video below:

I was intrigued by the appearance of the dissolved coating streaming down from the third Gobstopper and the creation of a misty layer above the other colors. After removing the remaining portions of the Gobstoppers, I mixed the contents of the beaker, wanting to see if there would be any change if I left it overnight. Would any material settle to the bottom of the beaker? It didn’t. In the morning, I restirred, then shone a laser pointer through the contents. The photo at the top of the post shows that a comment made by Benjamin Barth on Tom’s earlier post could be on the right track.

In the end, I don’t have any great, definitive answers about the Gobstopper system. However, the appealing part of this experiment and sharing it with students is that there do not appear to be any definitive answers out there. It’s one way to hook students and get them to dig into exploring a system to see what they can discover themselves.

Join the conversation.

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Comments 3

William Farmer | Fri, 04/25/2014 - 07:45


When reading your topic, I obviously clicked on the link to Toms' experiment. And a little carried away, I responded there, without looking at the dates.

To avoid a double disussion, I link here to my answer there and suggest we discuss is further there.



Erica Jacobsen's picture
Erica Jacobsen | Mon, 04/28/2014 - 00:18

So glad that the discussion continues and that others are looking into things that could be tried—it would be great to see what students do with it. I look forward to reading about Tom's students and their explorations.


Lowell Thomson's picture
Lowell Thomson | Wed, 05/07/2014 - 12:32

Inspired by your post, and Tom's post on M&Ms, I did an inquiry activity with my grade 10 intro chemistry class. The students were asked to bring in some sugar candy as homework for the next class. Then we simply went crazy, exploring what happened when the candy was put into a petri dish with some water. In hindsight, I should have structured the activity a bit more. 

The students wrote blog posts about their work where they posed some thoughts and questions. These can be found here:

I certainly plan on going down this path again, hopefully with a bit more structure.