American Museum of Natural History
What's the Big Deal About Water?
It may seem simple, but water is one of the most unique substances on Earth. An interactive online lesson describes its properties and importance in so many different situations. Learners interact with the lesson to learn the role water...
American Museum of Natural History
American Museum of Natural History: What Is Water?
This comprehensive article provides information about the physical properties of water, the importance of water as an Earth material, the processes and cycles that water undergoes on Earth, its importance to life on Earth, and why we...
University Corporation for Atmospheric Research
Ucar: Introduction to the Atmosphere
A detailed overview of the Earth's atmosphere, with explanations about atmospheric properties, the structure of the atmosphere, its four layers, atmospheric processes, energy heat transfer, conduction and convection, and radiation. All...