This lesson focuses on the diffusion of gas molecules across the cuticle membrane of sea spider legs and the role body size plays in the ability of sea spiders to uptake gases. Students construct model sea spider legs of varying diameters and use them to investigate the relationship between surface area-to-volume ratios and diffusion.
Ice that forms in the polar oceans is an important driver behind the global climate. This ice is physically different from frozen precipitation in a number of different ways. In this brief inquiry activity, students make qualitative observations about two types of ice cubes and deduce ice composition based on their observations. This activity may serve as an introduction to