Your student builds a sealed model of the water cycle in a bag using a gallon-size resealable bag, a quarter cup of water, and optional blue food coloring. Taped to a sunny window, the bag demonstrates evaporation as vapor rises, condensation as droplets form on the cooler upper surface, and precipitation as those droplets fall back into the water below. The observation section directs students to watch for all three stages, and a photo of a completed bag taped to a window gives a clear reference point. This sheet suits grades 3 to 5 and works equally well for a standalone earth science lesson or as a hands-on anchor activity inside a weather unit study.

Four think-and-answer questions close the lab, asking your homeschooler to explain what happened to the water over time, where condensation appeared, how droplets returned to the bottom, and how the bag model connects to the real water cycle on Earth. Completing those questions shows whether your student can apply observation to conceptual understanding, not just describe what they saw. The water cycle in a bag lab sheet works as a Charlotte Mason nature study tie-in or as a structured recording sheet inside a more formal homeschool science curriculum.