What minerals are in your toothpaste? A pencil? A telephone? This interactive resource adapted from the U.S. Geological Survey illustrates the variety of minerals used in everyday items found in kitchens, bathrooms, offices, and yards.

In this interactive activity adapted from Wake Forest University, students will observe the effect of mass on velocity and momentum in elastic and inelastic collisions. Includes background reading, a student handout, and discussion questions.

This multimedia resource produced for Teachers' Domain chronicles the 1980 volcanic eruption of Mount St. Helens. Featured are still images of the devastation, video of the eruption plume, and before-and-after satellite images of the affected region.

In this interactive activity from NOVA Online you can move an air mass over a mountain and see how several distinct microclimates are created.

Why do hot air balloons float? This resource from the NOVA Web site offers a series of interactive activities that illustrates the physics of hot air balloons.

Discover the difference between free-falling and weightlessness in this interactive activity from the NOVA: "Stationed in the Stars" Web site.

This interactive activity from NOVA Online shows four different ways in which caves are formed: by rainwater, waves, lava, and bacteria.

Learn what it takes to build an igloo from the best kind of snow to the most effective tools and other little-known facts about these traditional Canadian Inuit structures in this interactive activity from NOVA.

This link has many tools to help understand the revolutionary sciences and discoveries in genetics.

This interactive feature from the NOVA: "Leopards of the Night" Web site highlights the nighttime habits and abilities of a wide range of nocturnal creatures.

Nitrogen, one of the most abundant elements in the universe, is essential to life. This interactive activity adapted from the University of Alberta provides an overview of the nitrogen cycle. Includes background reading handout and discussion questions.

This interactive activity produced for Teachers' Domain presents users with three hypothetical scenarios in which they are challenged to design a wind power system that will meet their electrical needs.

In this interactive simulation of Ohm's law, adapted from the University of Colorado's Physics Education Technology project, students will adjust the voltage and resistance in a circuit, and observe how this affects the flow of current. Includes background reading material and discussion questions.

You're the geneticist now. In this interactive feature developed for the companion Web site for NOVA/FRONTLINE: "Harvest of Fear," use the latest in genetic technology to engineer your own "supercrop" of tomatoes.

In this interactive activity from ChemThink, students will examine the basic properties of matter at an atomic level and consider how various atoms affect the way a substance behaves.

This interactive periodic table developed for Teachers' Domain provides detailed information about the chemical properties of elements and illustrates the electron configurations that determine those characteristics.

In this interactive activity from NOVA Online, use the Fujita tornado intensity scale to assess the level of destruction left in the wake of actual tornadoes.

This interactive feature from the NOVA: "Leopards" Web site presents a wide variety of ways in which animals use coloration to their advantage.

This interactive activity, adapted from the Dolan DNA Learning Center, illustrates how Gregor Mendel used purebred yellow and green peas to show that some genes are dominant and others are recessive.

This interactive activity from the NOVA: "Dirty Bomb" Web site explores sources of radiation, both harmful and beneficial, natural and manmade.