This interactive activity for grades 8-12 features eight models that explore atomic arrangements for gases, solids, and liquids. Highlight an atom and view its trajectory to see how the motion differs in each of the three primary phases. As the lesson progresses, students observe and manipulate differences in attractions among atoms in each state and experiment with adding energy to produce state changes. More advanced students can explore models of latent heat and evaporative cooling. This item is part of the Concord Consortium, a nonprofit research and development organization dedicated to transforming education through technology.

Experiment with conductivity in metals, plastics and photoconductors. See why metals conduct and plastics don't, and why some materials conduct only when you shine a flashlight on them.

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.

This video from NASA features the Cosmic Origin Spectrograph (COS), which allows scientists to use spectrographic analysis to assess the composition of intergalactic material.

This Flash game develops students' computational fluency and flexibility. It can be played alone or with others. Players choose 6 face-down number cards, and the applet provides a target number. Number cards include one each of 25, 50, 75, and 100, and multiple copies of 1 to 10. The goal is to use the selected numbers and the four basic operations (addition, subtraction, multiplication, division) to arrive at the target. Players can ask the applet to Show a Solution, although others may be possible. Several rule and scoring variations are suggested. A full screen option facilitates use on an interactive board. (This game is not self-checking.)

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.

With this flexible Flash applet students can explore a wide range of concepts, including addition and subtraction, factors and multiples, fractions, ratios, and combinations. Users place, move and rotate virtual Cuisenaire Rods on a grid which can be enlarged, reduced, moved or printed. It contains a link to page of challenges which can take advantage of this tool.

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.

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.

Simulate the original experiment that proved that electrons can behave as waves. Watch electrons diffract off a crystal of atoms, interfering with themselves to create peaks and troughs of probability.

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.

In this visualization adapted from the University of Massachusetts Medical School, discover the role that dengue viral proteins play in a human cell as the virus prepares to replicate.

Why do objects like wood float in water? Does it depend on size? Create a custom object to explore the effects of mass and volume on density. Can you discover the relationship? Use the scale to measure the mass of an object, then hold the object under water to measure its volume. Can you identify all the mystery objects?

Why do objects like wood float in water? Does it depend on size? Create a custom object to explore the effects of mass and volume on density. Can you discover the relationship? Use the scale to measure the mass of an object, then hold the object under water to measure its volume. Can you identify all the mystery objects?

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.