This resource describes the pH scale and how changing pH levels affect water and the environment.

This lesson, developed by Mitch Albers, is designed to encourage students to "investigate the properties of water and develop an understanding of how water behaves in a lake environment." The lesson overview,...

The Hydrologic Cycle: Online Meteorology Guide Web site is maintained by the Department of Atmospheric Sciences of the University of Illinois at Urbana-Champaign. The guide describes the various aspects of the hydrologic...

USGS summary of the water cycle complete with diagrams, pictures and text. This is an excellent resource from the Geological Survey, that is great for students and can be included in the classroom along with lessons.

USGS School Water Science: This site offers information on many aspects of water, along with pictures, data, maps, and an interactive center where you can give opinions and test your water knowledge.