This video segment adapted from the Atmospheric Radiation Program explains the differences in the formation of tropical convective cloud systems over islands and over the ocean.

In this video segment adapted from ZOOM, two solar cookers are tested against a control to see which can cook a "s'more" faster.

In this video segment, ZOOM guest Cassie takes us on a tour of the coral reef near her home in Key Largo, Florida, and points out some of its unique features.

The concepts that underlie the fourth essential principle of climate literacy ("Climate varies over space and time through both natural and man-made processes.") are too complex for students in early and upper-level elementary school, but the foundational knowledge can be taught within existing curriculums and standards. This foundational knowledge will lead to understanding in later years. The author shows the correlation to the national science education standards, identifies misconceptions among elementary school students, suggests formative assessment probes, and identifies lessons and activities to make curriculum connections. The free, online magazine Beyond Weather and the Water Cycle is based on the seven essential principles of the climate sciences.

This interactive activity from ChemThink takes a closer look at a covalent bond--how it is formed and how the sharing of two electrons can keep atoms together.

This article introduces a free online collection of images, video clips, and animations that teachers can use in creating resources for use with students. The four steps in creating a video clip, an animation, or other resource are presented.

Students learn how DNA fingerprinting has been used in criminal investigations and discuss the limitations of and problems with DNA testing.

In this interactive activity from the Building Big Web site, investigate dams in distress and decide if they should be repaired, removed, or left alone.

This video segment from Evolution: "Darwin's Dangerous Idea," together with interviews with Daniel Dennett and James Moore, depicts Darwin struggling with publicizing his revolutionary theory.

In this video segment adapted from NOVA, scientists search for carbonized remains of plants preserved in lava flows to find out how long it has taken rain forests on Hawaii to regenerate after a volcanic eruption.

Without the work of decomposers, living organisms would eventually use up all the raw materials in the environment, and dead organisms and wastes would pile up. This video segment from Interactive NOVA: "Earth" describes the role of decomposers as the earth's great recyclers.

In this video segment adapted from ZOOM, cast members use a hair dryer to balance a ball in a stream of air, seemingly defying gravity.

In this video segment, the ZOOM cast is challenged to keep a ping pong ball in a funnel while the funnel is held upside down, seemingly defying gravity.

Why does an egg float in salt water? Learn about density and buoyancy in this video segment adapted from ZOOM.

Watch warm water float on top of cold water in this video segment adapted from ZOOM.

This video segment adapted from ZOOM offers a clever demonstration of buoyancy by showing how to pour a cup of air into a cup filled with water.

Will a grape float in oil? Will a metal nut sink in corn syrup? Watch as the ZOOM cast tests the buoyancy of a variety of liquids and objects.

This video segment from NOVA: A Desert Place describes the physical characteristics and organisms that define the desert biome.

In this video segment adapted from Design Squadí_í_íŹa PBS TV series featuring high school contestants tackling engineering challengesí_í_íŹlearn about the fundamentals of sound as student teams create percussive and stringed instruments for a local band.

In this video segment adapted from Design Squadí_í_íŹa PBS TV series featuring high school contestants tackling engineering challengesí_í_íŹstudents employ the concepts of tension and compression to build a suspension bridge without the aid of power tools.