The Atom

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

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.

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.

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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The Dating Game: Radioactive Carbon

In this media-rich essay from the NOVA Web site, learn about the atomic structure of radioactive carbon and how it can be used to determine the age of organic remains, such as bones and teeth.

Design an Ion Engine

Learn about ions and then design an ion engine to maximize thrust in this interactive activity adapted from NASA.

Electric Charges Interact

Experiment with electric charges to find out how they interact in this interactive activity adapted from NASA.

Everyday Radiation

How much radiation are we exposed to every day? Find out in this video segment adapted from FRONTLINE.

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Facts About Radiation

This document from the FRONTLINE Web site offers examples of everyday exposure to radiation.

FAQs About Nuclear Power

Nuclear physicist, Dr. Charles Till, answers questions about nuclear power in this interview from the FRONTLINE Web site.

Fission and Reprocessing: How They Work

This video-enhanced document from the FRONTLINE Web site explains how nuclear fission and nuclear reprocessing work.

Fusion: Testing the First Hydrogen Device

This video segment adapted from AMERICAN EXPERIENCE features original footage of the U.S. test of the first hydrogen device, code-named "Mike", that would trigger thermonuclear fusion.

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Fusion: The Hydrogen Bomb

Just after World War II, nuclear scientists turned their attention from fission to fusion. This video segment adapted from AMERICAN EXPERIENCE looks at the beginnings of thermonuclear power generation.

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Get Close to a Nuclear Fission Reaction!

Learn how scientists regulate a nuclear reactor in this animation-enhanced essay from the FRONTLINE Web site.

History of the Universe

This interactive timeline from the NOVA Web site recaps the theoretical origin and formation of the universe, and forecasts its eventual fate.

Ionic Bonding

In this interactive activity from ChemThink, learn how ionic bonds are formed and how an ionic bond structure is represented by its formula.

Measuring Bond Energy of an Ionic Compound

In this media-rich lesson, students investigate bond energy and the law of conservation of energy. They examine the chemistry behind instant cold packs by using a calorimeter to study the endothermic dissociation of ammonium chloride in water.

Nuclear Blast Damage

This illustrated document from the AMERICAN EXPERIENCE Web site examines the "zones of destruction" caused by nuclear weapons.

Nuclear Blast Footage

These video clips from the AMERICAN EXPERIENCE Web site feature actual footage of thermonuclear blast testing done in the 1950s.