We're studying volcanoes this week and next. I've added an extra week of volcanoes to our schedule, since we have a Magic School Bus volcano kit to add to the Intro to Science curriculum. Also, we had the fire station field trip this week and we have an aquarium field trip next week, so we're loosing 1.5 days of school over these 2 weeks.
Today we did an experiment with a soft boiled egg to demonstrate that volcanoes tend to form in the cracks between tectonic plates. Basically, you soft boil an egg, let it cool, tap it against a table to form cracks (tectonic plates), mark the cracks with a sharpie to make them stand out, and then - squish the egg. My daughter chickened out and so I ended up being the one to do the squishing. It was a bit messy, but sure enough - the "core" of the egg came out right along a "fault line" (though you might not be able to see the sharpie line in the picture below). Messy fun!