In Investigation One, students will begin their study of the water cycle by exploring the phases of evaporation and condensation. They will create models to simulate these phases using mirrors and beakers of water. Each model will represent variances in temperature that can exist between a body of water and the atmosphere. By comparing the models, students will discover that a difference in temperature between water on the Earth and the atmosphere causes evaporation and condensation of water.

In Investigation Two, students observe the physical properties of rock samples in comparison to other solids: wood, plastic, and metal. Through these observations, students discover that the relative weight and appearance of the samples do not necessarily depend on the composition of materials alone. That is, only by considering the combination of properties, can students correctly identify a substance.

Investigation Three introduces students to the collection phase of the water cycle. It provides them with the opportunity to create models that simulate the collection of groundwater and surface water. Students will also investigate the relationship between different types of soil and the collection of water as ground or surface water. Comparing these models will help students to better understand what is meant by the terms groundwater and surface water and reasons for the differences in the collection phase of the water cycle.

In Investigation Four, students will build a model to observe how pollutants enter the water cycle. Students will add pollutants to a model that represents a lake and its shore. By observing the interaction that occurs between land, groundwater, and surface water when pollutants are added to the environment, students will understand that the water cycle is an interconnected system in which pollutants can be transferred from one phase of the cycle to another and from one location to another.

Students continue their exploration of water pollution in Investigation Five. This investigation introduces students to the concept that pollutants introduced into the water cycle can have serious effects on the environment. Students will observe an experiment that simulates the effect of acid rain on non-living things, such as mountains, buildings, statues, etc. In addition, students will observe and construct several models to investigate whether pollutants affect living things, such as plants and animals. Through their investigation, students will come to realize both the direct and indirect effects of pollutants on the water cycle and surrounding ecosystems.