Watch beta decay occur for a collection of nuclei or for an individual nucleus.

This Cyberchase video segment features Bianca, who must figure out the fastest route to a movie premiere.

This article provides an overview of how teachers can use bibliotherapy to help students deal with social, emotional, and behavioral issues.

In this activity, a spinning bicycle wheel resists efforts to tilt it and point the axle in a new direction. Learners use the bicycle wheel like a giant gyroscope to explore angular momentum and torque. Learners can participate in the assembly of the Bicycle Wheel Gyro or use a preassembled unit to explore these concepts and go for an unexpected spin!

This ZOOM video segment shows how to create a self-contained environment and explores evaporation, condensation, and precipitation.

In this video adapted from NASA, two members of a NASA research team working to produce carbon nanotubes share some background behind this new technology, show examples of how it will be useful, and explain the various tests being performed to ensure readiness for spaceflight.

This activity provides instructions for using a flashlight and aquarium (or other container of water) to explain why the sky is blue and sunsets are red. When the white light from the sun shines through the earth's atmosphere, it collides with gas molecules with the blue light scattering more than the other colors, leaving a dominant yellow-orange hue to the transmitted light. The scattered light makes the sky blue; the transmitted light makes the sunset reddish orange. The section entitled What's Going On? explains this phenomena.

This video segment, adapted from NOVA scienceNOW, presents basic concepts of physics behind booming sand dunes. See how surface tension affects potential and kinetic energy and how it all works together to create sound.

Here’s a new “spin” on an old toy. In this modern adaptation of a classic toy—the spool racer—a plastic water bottle is propelled by energy stored in a wound-up rubber band.

In this demonstration of chemical change, the presenter blows breath into a methylene blue solution releasing carbon dioxide which acidifies the water and changes it from a bright blue color to green.

In this interactive activity from the Building Big Web site, use your knowledge of bridge design to match the right bridge to the right location in a fictitious city.

This brief article describes the historical methods of marking and measuring time. Among the instruments and methods discussed are sundials, water clocks, celestial motions, and mechanical clocks. Included are descriptions of the sources of inaccuracies of these methods. Links to related resources and a separate page of pedagogical notes are provided.

This activity asks students to visualize and construct three-dimensional objects from the two-dimensional drawings. Students are shown four solids composed of cubes, and they must reproduce the objects with manipulatives or sketch them on isometric dot paper. Ideas for implementation, extension and support are included along with a printable sheet of dot paper.

In this video segment adapted from ZOOM, the cast shows how the 34 steps in their Rube Goldberg invention use everything from gravity to carbon dioxide gas in order to accomplish one simple task: pouring a glass of milk.

In this video segment from ZOOM, Jillian explains how her simple machine uses marbles, levers, flowing sand, and a spinning wheel to water a plant.

How do you build a tunnel 32 miles long -- under water? This video segment adapted from Building Big, follows the construction of the Channel Tunnel (nicknamed "Chunnel"), the engineering wonder that connects England to France.

This problem helps children begin to understand the various properties of common geometric solid shapes. It also promotes naming, discussion and experimentation concerning their features, and requires them to justify their ideas. It asks students to judge the stability of nine configurations made from six common solids. The Teachers' Notes page includes suggestions for implementation, discussion questions, ideas for extension and support, and printable sheets.

When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.

When will objects float and when will they sink? Learn how buoyancy works with blocks. Arrows show the applied forces, and you can modify the properties of the blocks and the fluid.

8th grade student will apply Newton’s Laws to design, test and evaluate materials to create the most protective helmet for an activity of their choice. Students will use force sensors and Vernier software to analyze the force reduction for their helmets. The culmination of this project is for students to write and present a sales pitch to promote their helmet to their peers at an annual "conference."