HS - ESS2.C (C) - Properties of Water - FINAL (CLF)

Module: Properties of Water

DCI: ESS2.C (C) The abundance of liquid water on Earth’s surface and its unique combination of physical and chemical properties are central to the planet’s dynamics. These properties include water’s exceptional capacity to absorb, store, and release large amounts of energy, transmit sunlight, expand upon freezing, dissolve and transport materials, and lower the viscosities and melting points of rocks.

PE: HS-ESS2-5 Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes.

[Clarification Statement: Emphasis is on mechanical and chemical investigations with water and a variety of solid materials to provide the evidence for connections between the hydrologic cycle and system interactions commonly known as the rock cycle. Examples of mechanical investigations include stream transportation and deposition using a stream table, erosion using variations in soil moisture content, or frost wedging by the expansion of water as it freezes. Examples of chemical investigations include chemical weathering and recrystallization (by testing the solubility of different materials) or melt generation (by examining how water lowers the melting temperature of most solids).]

The ideas in this standard are: 

- liquid water on the Earth's surface is central to the dynamic process taking place 

- water has unique chemical and physical properties which play a role in these processes

- water has the capacity to absorb, store, and release large amounts of heat energy 

- water has the capacity to transmit sunlight

- water has the capacity to expand upon freezing

- water has the capacity to dissolve and transport materials

- water has the capacity to lower the viscocities and melting points of rocks

So there is quite a bit of content here, strictly related to the physical and chemical properties of water.  But, it seems as if all of this is really supposed to be in connection to the idea that the water cycle plays a role in the rock cycle.  We can probably ask one or two general questions about water's behavior, but then we need to get more into the PE.  We can use examples from the clarification statement as our "investigations". We can set up an "investigation" and then ask things like "which type of data would support the idea that water plays a role in the rock cycle?"