Other than the lactose intolerant, who doesn’t love chocolate? One thing that’s for sure is that kids do. Teaching the rock cycle is so often a dry, boring unit but with chocolate it can be made much more interesting, impactful, and can allow students to better understand the processes at hand! Using this STE(A)M (Science, Technology, Engineering, Art, Mathematics) activity can foster critical thinking, creativity, and intellectual growth in your students all under the guise of students getting free chocolate.
Use STE(A)M activities and challenges to make dry topics more exciting, to enhance your students’ understandings, and to build their scientific identities. #NSTA #ScienceTeaching #RockCycle #EDT431 @AnnMacKenzie
— Chris Grant (@cwistipher) October 28, 2018
Materials you’ll need:
- Varying colors and types work best – not all rocks are the same, right?
- M&Ms work well for this!
- Aluminum foil
- Some heat source like Bunsen burners or hot plates
- What you use and how it’s used can and should depend on the grade level.
In front of the class, place a piece of chocolate in an aluminum foil vessel and melt the chocolate. Once it cools and hardens, show the students how it looks – and then eat it!
Let them know that just like chocolate, rocks melt and re-harden all the time.
- For students to get a better foundation for the activity they’ll be doing, set up some station activities they can do to show how sedimentary, igneous, and metamorphic rocks form. They can shave some chocolate for sediment grains, then compact them together and try to form one solid block.
- They should partially melt that block of chocolate they just made with some chunks of other chocolate to see how metamorphic rocks form. They’ll put the foil over some hot water and once it slightly melts, use a toothpick to move it around! The different forms of chocolate should still be distinct.
- For igneous rocks, they can use the metamorphic rock they just made, with or without some additional chocolate, and COMPLETELY melt it and re-cool it. This is how igneous rocks form!
(this can also be done with crayons – but don’t let them eat their rocks if you use crayons!)
Let students form groups where they create a poster talking about how each of the three rock types can form from the others. This allows them to learn from each other, and allows you as the instructor to see what gaps they have in their knowledge.
This is where the students get to be more in charge of their rock cycle (and get to eat candy at the end). Challenge groups of students to create a rock of each type, with the most visible colors in it. For the sedimentary and metamorphic stages, this requires them to account for things like grain size, melting time and temperature, and how many colors they want to use. The group will present their rocks to the class and describe their process and at the end they all can eat it their own!
This is also another activity students could do at home that works similarly to this, but only for sedimentary rocks:
An exit slip posing a question that probes students to describe their process and how it modeled what geologists do to name/determine rock types would be a great elaborate!
Activity modeled from: https://www.earthsciweek.org/classroom-activities/chocolate-rock-cycle