Students explore the science of microbial fuel cells (MFCs) by using a molecular modeling set to model the processes of photosynthesis and cellular respiration—building on the concept of MFCs that they learned in the associated lesson, “Photosynthesis and Cellular Respiration at the Atomic Level.” Students demonstrate the law of conservation of matter by counting atoms in the molecular modeling set. They also re-engineer a new molecular model from which to further gain an understanding of these concepts.

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.

Scientists and engineers at Brookhaven are unlocking clues to Dark Matter and Dark Energy. Learn more through a series of mini-experiment

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.

Use water displacement and a mass balance to determine the density of various objects in this interactive simulation.

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.

Will a grape float in oil? Will a metal nut sink in corn syrup? Watch as the ZOOM cast tests the buoyancy of a variety of liquids and objects.

In this video from NOVA scienceNOW, learn how scientists detect potential signs of life on distant planets.

Seeing how energy and matter flows and is recycled from primary producers (autotrophs) to primary, secondary and tertiary consumers. [10:25]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

In this animation produced by WGBH and Digizyme, Inc., see how molecules of DNA are separated using gel electrophoresis, and how this process enables scientists to compare the molecular variations of two or more DNA samples.

A laboratory experiment where students classify matter into a homogenous mixture, heterogeneous mixture, solution, or pure substance. Also students will test for physical and chemical changes.

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

In this video from Evolution, an exploration of multi-drug resistant tuberculosis in the Russian prison system highlights one reason it is important to understand evolution.

In this video segment adapted from ZOOM, the cast investigates how the pitch of sound changes when they strike a variety of glasses filled with different amounts and types of liquids.

Kids have many ideas about how and why things fall based on their daily life experiences. However, many of these ideas are misconstrued. Learn from this video how to clear up these misunderstandings about gravity and help your students understand concepts of mass, weight, inertia, and air resistance. [9:51]

Created to teach students of the 21st century, SOPHIA is bringing the forms of energy straight to your fingertips. Become the commander of your own learning experiences as you take part in this energy tutorial. [4:00]

In this video segment adapted from NOVA scienceNOW, hydrogen fuel cell cars promise pollution-free driving, but will we see them anytime soon?