In this activity on page 10 of the PDF, learners develop an experiment to answer the following question: "How much water can the hydrogel in a baby diaper hold?" Use this activity to explore polymers, nanoscale science and nanotechnology. Safety notes: The powder in baby diapers is irritating to the eye and nasal membranes. Avoid shaking the diapers a lot, since doing so is more likely to irritate your nose. Always wear goggles when doing this activity. The gelled material can be disposed of in the trash -- do not put it in the sink, as it may clog the drain!