Learn the basics of why sweat cools your body down in this video. [5:13]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This video will explore the pH scale. See some examples of how to calculate the pH of water, orange juice, and bleach. [11:37]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Covers the structure and properties of water.

A free CK-12 account is required to view all materials.

Covers the structure and properties of water.

A free CK-12 account is required to view all materials.

Covers the importance of biochemical reactions involving water.

A free CK-12 account is required to view all materials.

Paul Andersen explains how water quality can be degraded by pollutants. Wastewater is the main source of water pollution and can be measured using the BOD (biochemical oxygen demand). Dead zones, cultural eutrophication, disease, and other pollutants are included. A 'Water Pollution Concept Map' is also available for download. [9:07]

Paul Andersen explains how water is unequally distributed around the globe through the hydrologic cycles. Seawater is everywhere but is not useful without costly desalination. Freshwater is divided between surface water and groundwater but must me stored and moved for domestic, industrial, and agricultural uses. [11:38]

Students learn about and experiment with the concept of surface tension. How can a paper clip "float" on top of water? How can a paper boat be powered by soap in water? How do water striders "walk" on top of water? Why do engineers care about surface tension? Students answer these questions as they investigate surface tension and surfactants.

Students construct three-dimensional models of water catchment basins using everyday objects to form hills, mountains, valleys and water sources. They experiment to see where rain travels and collects, and survey water pathways to see how they can be altered by natural and human activities. Students discuss how engineers design structures that impact water collection, as well as systems that clean and distribute water.

Students are presented with a short lesson on the difference between cohesive forces (the forces that hold water molecules together and create surface tension) and adhesive forces (the forces that causes water to "stick" to solid surfaces. The interaction between cohesive forces and adhesive forces causes the well-known capillary action. Students are also introduced to examples of capillary action found in nature and in our day-to-day lives.

Children design an animal habitat and talk about how the habitat provides the animal's basic needs -- shelter, water, and food -- using this block center activity. It includes three resources.

Through a series of five related sections, this 24 page pdf file examines a range of topics associated with states of matter including physical interactions between molecular units, bonding within molecular units, molecular units of chemical substances, and more.

As part of the General Chemistry Virtual Textbook, this site examines a variety of topics related to the hydrosphere and the oceans. Topics covered include where the water came from, the hydrologic cycle, Oceanic circulation, atmospheric circulation, surface currents of the oceans, and more.

An example of how ice can cause energy to transfer and reduce the temperature of water. [11:23]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

To increase students' awareness of possible invisible pollutants in drinking water sources, students perform an exciting lab requiring them to think about how solutions and mixtures exist even in unsuspecting places such as ink. They use alcohol and chromatography paper to separate the components of black and colored marker ink. Students witness first-hand how components of a solution can be separated, even when those individual components are not visible in solution.

Hydropower generation is introduced to students as a common purpose and benefit of constructing dams. Through an introduction to kinetic and potential energy, students come to understand how a dam creates electricity. They also learn the difference between renewable and non-renewable energy.

Students act as engineers contracted by NASA to create water filtration devices that clean visible particulates from teacher-prepared "dirty water." They learn about the worldwide need for potable water and gain appreciation for why water quality is an important issue for people on Earth as well as on the International Space Station. Working in groups, students experience the entire engineering design process, including a read-aloud book about the water cycle; a visiting water engineer presentation; their own online research about filter methods and designs; group brainstorming of designs (using ordinary household materials); filter construction and testing; redesign and retesting; lab book documentation of their notes, research, plans and results; and a summary poster presentation at a mini-engineering fair. Two design planning worksheets, a poster layout suggestion sheet and a grading rubric are provided.

This interactive resource adapted from the National Park Service describes the many forces that affect shorelines, including tides, weathering, erosion, and deposition. Includes background reading handout and discussion questions.

This article lists common misconceptions about states and changes of matter and the water cycle. It provides formative assessment probes and information about teaching for conceptual change.

This article describes six collaborative and real data projects that engage elementary students in collecting and sharing local data and communicating with students across the country and world.