This site is useful to find information about dissolved oxygen and the types of tests that are administered to determine the dissolved oxygen level.

Read a passage about the oxygen affinity of hemoglobin and answer the follow-up questions.

An explanation of the Earth's atmosphere and how it has evolved over geologic time.

As part of the General Chemistry Virtual Textbook, this site examines a variety of topics related to the Earth's atmosphere. Included in the discussion are topics such as prebiotic atmosphere, origin of atmospheric oxygen, carbon...

This experiment and video demonstration shows how students can break up water into hydrogen and oxygen gas with a simple electrolysis device.

The White Sands Research Facility is a main research and testing area for the Department of Defense, NASA, and commercial industry. White Sands works with rocket propulsion, properties of materials, hazards assessment, oxygen systems,...

Site describes process of photosynthesis, including role of pigment molecules, electron transport, ATP synthesis, and carbohydrate synthesis. Includes links to illustrative graphics.

An explanation of how the Earth's atmosphere has changed over time. Evidence that helped scientists understand these changes is presented.

Explore the periodic table like never before! This downloadable program module for students comes absolutely complete with teacher modules, student assessments, PowerPoints, Excel spreadsheets, historical text readings and more. Students...

Instructional module focusing on the carbon cycle. Discussion includes the biological and geological components of how carbon moves through the atmosphere, lithosphere, and hydrosphere. Site also includes an interactive practice quiz and...

This article discusses how plants and microorganisms, until recently, have mostly controlled how much carbon dioxide is released into an ecosystem, and explains how this process works. Humans' burning of fossil fuels has upset the...

Students learn about the giant impact hypothesis for the Moon's formation, and how the Apollo Moon rocks have contributed to scientists' understanding of the Moon.

Learn about the important resources our land offers us: food, water, oxygen, building materials, and more. Discover how scientists have been mapping land for years trying to prevent disasters and to collect environmental information.

This is a brief biography from The Nobel Foundation overviewing Paul Ehrlich's (1854-1915 CE) contributions to the world of medicine. Read about studies in immunology, for which he was honored through the 1908 Nobel Prize in Medicine, an...

An interactive lab simulation demonstrates the effects of increased carbon in the atmosphere and how that increase contributes to climate change. A data table for student records is available for download.

A detailed overview of the chemistry of ozone and its role in the atmosphere. Students learn about the benefits and hazards of ozone. All information is reinforced through pictures, graphs, and learning activities. Learning activities...

An organized resource highlighting properties of freshwater and water quality concerns.