Delicate Balance

Water Cycle

Grades 4-9

Water cycles in an observable process.

• Construct an explanation using models or representations.

• Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students' own experiments) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

• Apply scientific ideas, principles, and/or evidence to construct, revise and/or use and explanation for real-world phenomena, examples, or events.

• Apply scientific reasoning to show why the data or evidence is adequate for the explanation or conclusion.

• Develop and/or use a model to predict and/or describe phenomena

• Develop a model to describe unobservable mechanisms.

• Students learn matter is conserved because atoms are conserved in physical and chemical processes. They also learn within a natural or designed system, the transfer of energy drives the motion and/or cycling of matter. Energy may take different forms (e.g. energy in fields, thermal energy, energy of motion). The transfer of energy can be tracked as energy flows through a designed or natural system.

• Water cycles among land, ocean, and atmosphere, and is propelled by sunlight and gravity. Density variations of sea water drive interconnected ocean currents. Water movement causes weathering and erosion, changing landscape features. Complex interactions determine local weather patterns and influence climate, including the role of the ocean.