Where does the water go? Using a Shell-less Egg to Investigate Osmosis
The Challenge
Your class has six eggs whose shells have been dissolved. Three will be placed in tap water and three in salt water. Your job is to predict what will happen, contribute one measurement to the class experiment, and use all six eggs to figure out how water moved across the egg membrane.
Purpose
Students use shell-less eggs as a model for investigating osmosis. The central value of this lab is not simply seeing one egg gain or lose mass. The class creates replicated data, combines the results, and uses quantitative evidence to reason about water movement in hypotonic and hypertonic environments.
