100's Day

What does 100 look like? Sound like? Feel like? In this video from Curious George, explore the many ways to measure 100 things.

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Acids and Bases: Cabbage Juice Indicator

In this video segment, the ZOOM cast demonstrates how to use cabbage juice to find out if a solution is an acid or a base.

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Acids and Bases: Kitchen Chemistry

In this interactive activity from the ZOOM Web site, search for chemistry clues and experiment with acids and bases in a virtual kitchen.

Acids and Bases: Making a Film Canister Rocket

In this video segment, ZOOM cast members mix different amounts of baking soda and vinegar to see which combination produces the most carbon dioxide for launching a film-canister rocket.

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Acids and Bases: Testing Rocket Cars

In this ZOOM video segment, cast members make bottle rocket cars using lemon juice and baking soda, and experiment with different ways of launching the cars.

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Acids and Bases: Testing Rockets

What happens when you mix baking soda and lemon juice? Watch the ZOOM cast launch a rocket using kitchen chemistry.

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Air Is Matter

This collection of still images presents different ways to visualize air, from billowing sails to windblown hair to tornadoes.

Air Is Matter

Students investigate air and how it is something that occupies space, has mass, and exerts pressure.

Air Power: Experimenting with Balloons

In this video segment adapted from ZOOM, cast members experiment with the amount of air expelled first from a balloon, then through a straw attached to it, and see how both affect a balloon's behavior.

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Air Power: Making a Hovercraft

In this video segment adapted from ZOOM, cast members make their own hovercraft and demonstrate how the air leaking out of a balloon can make a plastic plate hover above a table.

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Anatomy of a Firework

There's more to a fireworks display than meets the eye. This interactive activity from the NOVA Web site looks at the technology behind each burst of light.

Atmospheric Pressure

Did you know that air has weight? This illustrated essay from the NOVA Web site explores conditions that affect air density and atmospheric pressure.

The Atom

In this interactive activity from ChemThink, take a closer look at atomic structure, properties, and behaviors.

Atom Builder

Build a carbon atom out of up quarks, down quarks, and electrons in this interactive activity from the NOVA Web site.

Atomic Arrangements in Solids

This video/animation asks the question "So if the same molecules are in the solid, liquid, and vapor forms of water, why are their properties so different?" The properties of a material are affected not just by the kinds of atom in it, but also by how they are arranged, and how free they are to move around. Forms of carbon are introduced, from graphite to buckyballs.

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Atomic Structure of an Alloy

Learn about the atomic structure of bronze, a copper alloy, in this video excerpt from NOVA: "Hunting the Elements."

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Atoms: The Space Between

This video segment adapted from A Science Odyssey takes a look at the scale of the atom and the tremendous amount of space between the electrons and the nucleus. If all this empty space exists in matter, how can any substance be solid?

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Balloon Brain: Designing a Helmet

In this video segment adapted from ZOOM, cast members are challenged to design protective headgear for a water balloon using what they know about the properties of the materials available.

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The Beginnings of the Telescope

This animated essay from the NOVA Web site examines the design of Galileo's refracting telescope and Sir Isaac Newton's reflecting telescope.

Bend, Twist and Break: Beyond the Laboratory

Dr. Chris Muhlstein explains that when scientists study fracture surfaces from controlled experiments to understand the resulting shapes and features, they can use their understanding to deduce what happened when they were not around to see the material fail or break. Further they can predict what will have to a larger or smaller piece of material under stress. This process is how scientists and engineers translate a lab experiment into a design for an airplane, bridge or even a bike frame.

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Bend, Twist and Break: Breaking Glass

Dr. Chris Muhlstein explains that researchers learn about the scientific basis for failure of materials by running experiments in the lab, using a simple shape like a glass rod to calculate the strength of material and predict its failure. The same tests can be done at the micro and nano scale using tiny specimens. Students can run a similar experiment with a bar of chocolate.

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Bend, Twist and Break: Fracture Surfaces

Dr. Chris Muhlstein explains that fracture surfaces can reveal how and why a material has failed. An image of a fracture surface has features or shapes that we can use to understand where a material failed and why. Scientists use an optical microscope or a scanning electron microscope to read a fracture surface at high magnifications, much like we read maps to find our way.

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Bend, Twist and Break: The Bridge

Dr. Chris Muhlstein explains that the arrangement of atoms in a material determines the properties. He drops an iPod to illustrate how the arrangement of atoms can protect it from damage; he narrates footage of the collapse of the Tacoma Narrows Bridge in the 1940s to show how the deformation of materials can cause the collapse of a structure.

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Birth of a Supernova, Type Ia

In this interactive activity from NOVA Online, learn about a type of exploding star — a Type Ia supernova — that is so bright that astronomers can measure the distance to the galaxy in which it resides, and even learn which elements make up the star.

Birth of a Supernova, Type II

In this interactive activity from NOVA Online, learn about a type of exploding star — a Type II supernova — that is so large it has a mass 10 times greater than the mass of our Sun.

Blacker Than Black

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.

A Boat That Floats

In this video from Curious George, children build boats out of everyday materials and then predict and observe whether the boats sink or float.

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Bouncing Science

In this lesson, based on the Science Friday segment Physics of Basketball, students explore the properties of various balls from different sports, and discuss why the design of each ball is suited to its associated sport.

Breaking Things on Purpose

*Materials such as metals (aluminum, iron, copper, etc.), ceramics (silicon carbide, porcelain) or polymers (milk jugs made of polyethylene) are tested by scientists and engineers to reveal certain mechanical properties such as the maximum stress a material can withstand. The stress at which a material breaks is a measure of its strength. In this lesson you will be testing the strength of a delicious material you know as chocolate!

Breathing Blue

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.

Build a Steroid

In this interactive activity from NOVA, learn about the molecular structure of steroids. See the intermediate molecules that are part of the pathway for synthesizing cortisone from diosgenin.

Building Blocks of Matter

Structure of matter.

Buoyancy Basics

This illustrated demonstration from the NOVA Web site explains the concepts of buoyancy and density by showing what happens when different kinds of wood blocks are dropped in water.

Buoyancy Brainteasers: Balloon-in-Car Puzzler

This interactive brainteaser from the NOVA Web site challenges you to explain the behavior of a helium-filled balloon in a moving car.

Buoyancy Brainteasers: Boat-in-Pool Puzzler

This interactive brainteaser from the NOVA Web site challenges you to figure out what happens to the water level when a rock is resting in a boat and when it is submerged in water.

Buoyancy Brainteasers: Buoyancy Question

This interactive brainteaser from the NOVA Web site challenges you to figure out what causes an object to sink.

Capturing Carbon

In this video segment adapted from NOVA scienceNOW, a scientist, inspired by his daughter's science fair project, develops a synthetic "tree" to remove excess carbon dioxide from the air.

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Carbon Cycle Diagram

This diagram from NASA's Earth Science Enterprise illustrates Earth's carbon cycle.

Cheese: Not the Same Mold Story

In this video, Science Friday investigates the secret life of cheese.

Cheesy Chemistry

Students will learn how to make a simple cheese using kitchen utensils and household ingredients in this lesson based on the Science Friday video Cheese: Not the Same Mold Story.

Chemical Bonds

This interactive activity developed for Teachers' Domain demonstrates how attractive forces between atoms create chemical bonds, resulting in the formation of molecules and compounds.

The Chemistry of Makeup

In this video from DragonflyTV, join Jazi and Danielle as they experiment with different combinations of everyday ingredients in order to create and test batches of lip gloss.

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Chernobyl: What Really Happened?

This text excerpted from Richard Rhodes' book, Nuclear Renewal and reprinted on the FRONTLINE Web site examines the causes of the Chernobyl accident.

Columns: Experimenting with Balloons

Watch the ZOOM cast find out how many balloons filled with air and then with water are required to support the weight of a cast member.

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Comparing the Density of Liquids, Solids, and Gases

Students compare the relative densities of different liquids and then solids, and also explore the density of air versus the density of water.

Cooking Cookies with Solar Power

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

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Cooking with Sugar

Find out about the chemistry of candy and how sugar reacts at different temperatures to become fudge, caramel, lollipops, and more in this interactive activity adapted from the Exploratorium.

Cosmic Origin Spectrograph

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

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Counting Neutrons on the Moon

Find out how scientists are using a neutron detector onboard a satellite to try to find water on the Moon in this video adapted from NASA.

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Covalent Bonding

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.