Candy bars can help you teach students about the earth's crust.
Using candy can be a good way to motivate your students by promising a tangible reward at the completion of their studies. By tying scientific concepts to real-world objects, it also helps bring education to life. Fortunately for geography or earth science teachers hoping to use candy in the classroom, it can help teach concepts such as planetary layers, plate tectonics and triboluminescence.
Show the Layers of the Crust
This activity requires the use of a candy with multiple layers enrobed in chocolate --- preferably something filled with nougat, caramel, or both. Pull the candy apart slowly, and show your students how the fluid center deforms, while the brittle crust breaks. You can explain how this models the difference between the Earth's crust (on which we live) and the highly viscous mantle --- the nougat and caramel deform smoothly, but the candy shell breaks: if anybody was living on the surface of the candy bar, they would experience these breaks as earthquakes.
Map Earthquake Activity
The United States Geological Survey (USGS) maintains a database of earthquakes that you can use to track earthquake intensity (see Resources). Get a list of all the earthquakes over the last 30 days, and use small pieces of multicolored bite-sized candy to plot their locations on a map (this also allows you to teach latitude and longitude if your students aren't already familiar with it). Use different colors to represent different levels of the moment magnitude scale (the earthquake scale that replaced the Richter scale). Ask your students what patterns they see --- the candies will all be clustered around continental plates, and you can use these clear boundaries to discuss plate tectonics.
Demonstrate Triboluminescence
One mysterious and interesting occurrence associated with earthquakes is the phenomenon of "earthquake lights," a glow in the sky that accompanies or precedes an earthquake. Although their cause isn't well understood yet, one possible answer is that they're related to triboluminescence --- generated when the bonds of a material are broken, like when rocks are crushed by the movements of the earth in an earthquake. You can demonstrate this effect by turning the lights out and having your students crush a hard candy such as a Life Saver (or even a sugar cube) in their mouths while looking into a mirror. As the candy is crushed, it will appear to spark or glow --- this same phenomenon, occurring on a much larger scale with quartz crystals instead of sugar, could be responsible for earthquake lights.
What to Keep in Mind
Although candy-related activities can be a fun way to engage your student's attention, you should check with your school's wellness specialist before developing any lesson plans that involve consumables. The wellness specialist will be able to tell you if there are any special requirements you should be aware of --- for example, they'll know in advance if one of your students is allergic to nuts or sensitive to gluten, which is often found in chocolate as a stabilizer.
Tags: your students, earthquake lights, help teach, nougat caramel, plate tectonics, wellness specialist
