My local chapter of the American Chemical Society sponsors an annual event at a local mall called “Chemistry at the Mall”. The event is in celebration of National Chemistry Week. This year’s theme is “The Sweet Side of Chemistry – Candy”. I advise an ACS ChemClub and we hosted a table at “Chemistry at the Mall”. Ten student members worked shifts from 11am – 4pm. This was a great way to get involved with my local chapter and meet some other members. My students had a great time providing outreach and introducing young children to chemistry.
The main activity allowed children to add a few drops of food coloring to a pile of shaving cream, swirl it around, press a notecard into it and come up with a fun design printed on their card. This activity, Colorful Lather Printing, is a JCE Classroom Activity published in the Journal of Chemical Education. Two other activities were related to the theme. The first is taken from another JCE Classroom Activity, A Sticky Situation.: Chewing Gum and Solubility. (Both Classroom Activities are available without a subscription to JCE.) Children were provided a small piece of bubble gum. They could then add a chocolate chip to chew along with the gum. They quickly found that “like dissolves like” and the gum dissolved in their mouths. The last activity showed that the letters (S and M) on Skittles and M&Ms separate off of the surface of the candy when soaked in water. I read about this in Floating Letters written by Marilyn Duerst. The article is published in the 2014 National Chemistry Week edition of Celebrating Chemistry. The letters are insoluble in water and an edible glue is used to stick them to the surface of the candy. The glue dissolves in warm water and the letters float to the surface of the water since they are less dense.
The event was mostly geared to children, but parents and other adults enjoyed our table and many commented that they had learned something.
We had not participated in this event before, so I was unsure of amounts of supplies to purchase. With that in mind, I purchased 400 notecards, 10 large cans of foamy shaving cream and two boxes of food coloring (with four bottles each). I wanted to be sure to have enough of these supplies to manage every child that came to the table. This is a messy activity, so I also had a bucket for waste foam (a garbage can is fine, but I was unsure if one would be available), several rolls of paper towel, paper plates and rulers (for scraping the foam off the cards). I lined the table with freezer paper and kept replacing it to help keep things somewhat tidy. Over 250 children attended. We used over 200 cards, 7 cans of shaving cream and both boxes of food coloring. I was not worried about running out of supplies for the other two activities. I purchased just one bag of milk chocolate chips and one bag of tiny pieces of bubble gum for the Sticky Situation activity. I bought a large bag of Skittles and another of M&Ms for the last activity. We had several small cups of water for children to drop the candies in the water… letter side up. They could do the other activities and when they came back to their cup, the letters were floating at the surface. The student workers emptied the cups into the bucket I had on hand as they rotated new cups in. I had a lot of the candy left over.
It is helpful to write out directions and explanations for student workers. I left laminated copies out for reference. These activities were fairly simple, but if you will be prepping for a similar event, you may want to create some laminated copies to set on the table that give step by step instructions and/or explanations for children/parents that are participating.