Slime Science

What better way is there to celebrate being off of school and on spring break than making slime at the library? I asked myself this question while developing my library's spring programming schedule, and I decided that our branch was absolutely going to get slimed.

The Slime Science program involved around 25 school-age kiddos out on the library's patio--by all means, do this program outdoors, as it is MESSY! Once everyone had gotten settled onto their sit-upon cushions, I showed them how to make our slime: I mixed about three cups of corn starch in a clear tub with approximately two cups of water. It takes a good five-ish minutes to stir these ingredients together into a slime, and I took that time to chat with everyone about states of matter. The kiddos were quick to name solids, liquids, and gases, and they had good examples of each and were able to mention some of their properties (good job, science teachers!).

As my slime began to reach completion, I asked everyone if they thought a substance could act like two different types of matter. This question certainly piqued their interest, and I introduced the concept of non-Newtonian fluids--in this case, a substance that acts like both a solid and a liquid. This slime acts like a solid when pressure is applied to it (e.g., if you try to squish it or shape it, it resists changing its shape), but it will flow and drip like a liquid when left alone. They loved learning this term; I'm a firm believer in not trying to simplify language for children.



Acting like a solid...

...and like a liquid!

At this point I invited the kiddos to come up to the tub of slime in small groups to touch it and see it for themselves. A great demonstration pattern was to invite them to slowly dip a finger in the slime; it feels like a slightly thick water. I would then tell them to try to yank the finger out quickly; at this sudden application of force, the slime resists and the finger doesn't slide right out. The looks of fascination and excitement on the kiddos' faces when they experienced this phenomenon for themselves were great.

After we had cycled everyone through the demonstration tub, it was time for us all to make our own slime. I had prepared baby food jars of corn starch for all of the participants, and with the help of a colleague and a teen volunteer, every program participant added some food coloring and water to their jars. They each went back to their sit-upons to stir their mixtures with a popsicle stick until the right consistency was reached. I had anticipated needing more corn starch to balance the overly watery batches of slime, and it was a good thing I had--at least half of the kiddos needed to add more corn starch to their jars to get good slime. This bit of trial and error gave us great opportunities to talk about science and experimentation, and it helped pass the bit of time it took to get everyone's slime ready.

We spent the last bit of the program pouring our slimes into our hands and playing with its solid-and-liquid properties. Some of the kiddos said it was gross; some said it seemed impossible how the slime could be both runny and firm; and some said they couldn't wait to share the experiment with siblings and parents at home. Everyone got to take home their jars of slime--each jar affixed with a label warning not to put it down the drain. My library colleagues mentioned they heard all sorts of excited and positive comments about the program as kiddos and their families made their way out of the library. Educational and fun!

One of the best parts of this program is how easy and inexpensive it is. If you regularly collect baby food jars from coworkers, the only real costs are corn starch and food coloring. As far as prep for the program was concerned, I did spend a bit of time getting the individual jars ready with labels and corn starch. Other than that, all of the work was during the program helping everyone to get a good-consistency slime.

Oh, and cleaning up did take a bit of time. I did mention this program was messy, right?