Elementary, K through 5

Elementary Physical Science

Plant + Algae = Total Photosynthesis for the Earth

At elementary level, physical science comes down to matter and energy. The algae in the kit are three to five microns across, roughly twenty times smaller than the best a hand lens can resolve, so students genuinely cannot see them and have to find them by what they do to light. That is the cleanest version of matter is made of particles too small to be seen that a classroom can run, and it ends with the particles being recovered rather than taken on trust. The energy half is the same bag read a different way: every bit of energy in a brine shrimp came through the window as sunlight.