2.

Understand the unique role water plays on Earth, including:<ul><li>ability to remain liquid at most Earth temperatures</li><li>properties of water related to processes in the water cycle: evaporation, condensation, precipitation, surface run-off, percolation</li><li>dissolving of minerals and gases and transport to the oceans</li><li>fresh and salt water in oceans, rivers, lakes, and glaciers</li><li>reactant in photosynthesis.</li></ul>