Semiconductors are the materials that make modern electronics work. Learn about the basic properties of intrinsic and extrinsic or 'doped' semiconductors with several visualizations. Turn a silicon crystal into an insulator or a conductor, create a depletion region between semiconductors, and explore probability waves of an electron in this interactive activity.

Dope the semiconductor to create a diode. Watch the electrons change position and energy.

This article, written for students in grades 4-5, introduces the concept of albedo and describes the shrinking of Arctic sea ice. Modified versions are available for students in younger grades.

This activity is an investigation of free fall and projectile motion through a track and field situation.

In this decision-making exercise, students investigate what would occur if a dam were built along Nanticoke Creek, a real stream just north of West Corners near the Village of Endicott, New York. They will use topographic maps to determine how much area would be flooded by the new reservoir, to study river drainages, and to consider the impacts of dams on a region. They must also consider rivers in the context of their relation to humankind. The exercise can be extended to other, more local locations having similar topography.

This fact card discusses the shape of space and how light is affected by the amount of dark matter and energy in the universe. MAP's microwave detection gives us enormous insight into the creation of this matter and energy. Note: this resource was published prior to the mission name change from MAP to WMAP (Wilkinson Microwave Anisotropy Probe) to honor Dr. Wilkinson.

In this adapted ZOOM video segment, cast members calculate how much water they each use during a typical shower. They compare their results to their original predictions.

Why do the lights turn on in a room as soon as you flip a switch? Flip the switch and electrons slowly creep along a wire. The light turns on when the signal reaches it.

Why do the lights turn on in a room as soon as you flip a switch? Flip the switch and electrons slowly creep along a wire. The light turns on when the signal reaches it.

Students build and use a very basic Coulter electric sensing zone particle counter to count an unknown number of particles in a sample of "paint" to determine if enough particles per ml of "paint" exist to meet a quality standard. In a lab experiment, student teams each build an apparatus and circuit, set up data acquisition equipment, make a salt-soap solution, test liquid flow in the apparatus, take data, and make graphs to count particles.

In this activity, students investigate convection as it applies to Earth processes. They will assemble a model using a bread pan to view convection in two paired cells. They will also investigate the strengths and weaknesses of the model thay have constructed and answer some questions about what they are seeing.

In this activity, learners build a simple mechanism that regulates the "escape" of energy released by a falling weight by portioning it into discrete amounts. Escapements are found in mechanical clocks, such as those driven by a pendulum or a spring. Learners will build the wrapping form of escapement said to be used in a fifteenth-century German clock.

This video segment from IdahoPTV's D4K lists, describes and shows examples of the 6 simple machines and how they make work easier.

Students apply the mechanical advantages and problem-solving capabilities of six types of simple machines (wedge, wheel and axle, lever, inclined plane, screw, pulley) as they discuss modern structures in the spirit of the engineers and builders of the great pyramids. While learning the steps of the engineering design process, students practice teamwork, creativity and problem solving.

This activity describes a simple clear demonstration of electric generators (Faraday's Law) and electric motors (Lorentz Force). This demonstration can be used as an interactive lecture demonstration.

This is a calculus-based physics textbook meant for the type of freshman survey course taken by engineering and physical science majors, or for AP Physics C. It uses a nontraditional order of topics, with energy coming before force. For instructors who prefer the traditional sequence, there is a drop-in replacement for ch. 0-4, Mechanics, that covers force before energy. My text for the type of course usually taken by biology majors is Light and Matter.

In this activity, learners create a tiny electric, motorized dancer. Learners use the interactions of magnetism and electric current to make a wire spin, while displaying the Lorentz Force in action. This lesson guide provides one of many ways to build the spinner and links to other methods.

Is it a tumor? Magnetic Resonance Imaging (MRI) can tell. Your head is full of tiny radio transmitters (the nuclear spins of the hydrogen nuclei of your water molecules). In an MRI unit, these little radios can be made to broadcast their positions, giving a detailed picture of the inside of your head.

In this activity, students engage in a simulation of the international negotiation process in order to convey how the international community is responding to climate change. Participants learn firsthand about the interests of different countries and the range of policy responses to mitigate future climate change.

This is in class lab activity where students will explore the buoyant force.