This reference discusses the composition and chemistry of seawater, and how they affect organisms in the sea. Topics include salinity, temperature, density, dissolved gases, dissolved nutrients, and pH.
This site contains a mineral database with access to 4,339 individual mineral species descriptions with links and a comprehensive image library. Mineral data on individual species are linked to a mineral table by crystallography, X-Ray powder diffraction, chemical composition, physical and optical properties, Danas new classification, Strunz classification, mineral specimen images, and alphabetical listings of mineral species. There are extensive links to other sources of mineral data and information. Visit the Whats New section for details.
In this activity, learners make a 3-D model of DNA using paper and toothpicks. While constructing this model, learners will explore the composition and structure of DNA. The activity also gives suggestions for alternate materials and challenges to explore.
This United States Geological Survey (USGS) website explains volcanic gases and their effects on the Earth and its life. The report discusses gases trapped in magma below the Earth’s surface as the driving force of volcanic eruptions. Types of gases, such as sulfur dioxide and carbon dioxide, and their potential effects are described. A comparison of volcanic gas composition in three different volcano types is also given.
