Diffusion is the net movement of particles from areas of high concentration (number of particles per unit area) to low concentration. In this activity, students use a molecular dynamics model to view the behavior of diffusion in gases and liquids.

This activity is a field investigation where students will observe three areas with high sensitivity to pollution, and test water quality in two of the locations.

This activity is a guided inquiry on the density of two liquids and salt. Students will then create their own experiment to back their findings.

This lab activity shows students the Law of Conservation of Matter and intermolecular forces by having them dissolve packing peanuts in acetone.

This activity is a guided inquiry where students will investigate if water molecules have any space between them.

This lab introduces basic chemistry concepts in molecular interactions, measurements, prediction, and critical thinking.

In this interactive activity from the Building Big Web site, think like an engineer and use your knowledge of dome design to match the right type of dome to the right location in a fictitious city.

This video segment adapted from NASA's Goddard Space Flight Center discusses how a drought can have negative effects locally, for example by increasing the number of forest fires, and also globally, for example by impacting air quality thousands of miles away.

This video segment adapted from NASA's Goddard Space Flight Center describes El NiŰ__ŒóíŠo, how it forms, and the chain reaction of consequences it triggers around the globe.

This video segment adapted from NASA's Goddard Space Flight Center explains how hurricanes develop and why there are fewer hurricanes in the Atlantic Ocean in strong El NiŰ__ŒóíŠo years.

This video segment adapted from NASA's Goddard Space Flight Center shows how integral satellites are to everyday life and describes the different types, including orbital and geostationary.

This interactive activity from the Adler Planetarium explains the reasons for the seasons. Featured is a game in which Earth must be properly placed in its orbit in order to send Max, the host, to different parts of the world during particular seasons.

This video segment adapted from NOVA tells the tragic story of two Japanese seismologists who disagreed about the threat of earthquakes in the early twentieth century. Today, seismologists in California offer residents a probability of risk that an earthquake might occur.

In this video segment adapted from NOVA, animations are used to show how the hills around Los Angeles were formed by earthquakes at small thrust faults that extend outward from the larger San Andreas fault.

The history of earthquakes in the San Francisco Bay area is plotted on a digital map and analyzed in this video segment adapted from NOVA.

In this video segment adapted from NOVA, a geologist digs a trench along the San Andreas Fault to reveal three thousand years of earthquake history. Information from the layers of sediment may help geologists to predict earthquakes.

This video segment adapted from NOVA uses historical illustrations, photographs, and animations to explain how seismographs work, the difference between P and S waves, and the Richter scale.

To gain an understanding of mixtures and the concept of separation of mixtures, students use strong magnets to find the element of iron in iron-fortified breakfast cereal flakes. Through this activity, they see how the iron component of this heterogeneous mixture (cereal) retains its properties and can thus be separated by physical means.

Students make edible models of algal cells as a way to tangibly understand the parts of algae that are used to make biofuels. The molecular gastronomy techniques used in this activity blend chemistry, biology and food for a memorable student experience. The models use sodium alginate, which forms a gel matrix when in contact with calcium or moderate acid, to represent the complex-carbohydrate-composed cell walls of algae. Cell walls protect the algal cell contents and can be used to make biofuels, although they are more difficult to use than the starch and oils that accumulate in algal cells. The liquid juice interior of the algal models represents the starch and oils of algae, which are easily converted into biofuels.