I mostly use this exercise as a "see, most of your radiation does is NOT from nuclear plants." I have used this in both General Chemistry and Inorganic Chemistry when doing a nuclear chemistry or energy production unit.
Helps if you have some sense of the elevation you live at, and/or the elevation of places that your students came from.
Students love this exercise. They are quite surpised at the difference of living near a coal vs. a nuclear plant.
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