Explore the interactions between various combinations of two atoms. Turn on the force arrows to see either the total force acting on the atoms or the individual attractive and repulsive forces. Try the "Adjustable Attraction" atom to see how changing the parameters affects the interaction.

This learning video continues the theme of an early BLOSSOMS lesson, Flaws of Averages, using new examples—including how all the children from Lake Wobegon can be above average, as well as the Friendship Paradox. As mentioned in the original module, averages are often worthwhile representations of a set of data by a single descriptive number. The objective of this module, once again, is to simply point out a few pitfalls that could arise if one is not attentive to details when calculating and interpreting averages. Most students at any level in high school can understand the concept of the flaws of averages presented here. The essential prerequisite knowledge for this video lesson is the ability to calculate an average from a set of numbers. Materials needed include: pen and paper for the students; a blackboard or equivalent; and coins (one per student) or something similar that students can repeatedly use to create a random event with equal chances of the two outcomes (e.g. flipping a fair coin). The coins or something similar are recommended for one of the classroom activities, which will demonstrate the idea of regression toward the mean. Another activity will have the students create groups to show how the average number of friends of friends is greater than or equal to the average number of friends in a group, which is known as The Friendship Paradox. The lesson is designed for a typical 50-minute class session.

Students construct paper recombinant plasmids to simulate the methods genetic engineers use to create modified bacteria. They learn what role enzymes, DNA and genes play in the modification of organisms. For the particular model they work on, they isolate a mammal insulin gene and combine it with a bacteria's gene sequence (plasmid DNA) for production of the protein insulin.

Play with objects on a teeter totter to learn about balance. Test what you've learned by trying the Balance Challenge game.

How do you know if a chemical equation is balanced? What can you change to balance an equation? Play a game to test your ideas!

Students follow the steps of the engineering design process as they design and construct balloons for aerial surveillance. After their first attempts to create balloons, they are given the associated Estimating Buoyancy lesson to learn about volume, buoyancy and density to help them iterate more successful balloon designs.Applying their newfound knowledge, the young engineers build and test balloons that fly carrying small flip cameras that capture aerial images of their school. Students use the aerial footage to draw maps and estimate areas.

Experiment with a helium balloon, a hot air balloon, or a rigid sphere filled with different gases. Discover what makes some balloons float and others sink.

Students explore static electricity by rubbing a simulated balloon on a sweater. As they view the charges in the sweater, balloon, and adjacent wall, they gain an understanding of charge transfer. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). The simulations are animated, interactive, and game-like environments.

Why does a balloon stick to your sweater? Rub a balloon on a sweater, then let go of the balloon and it flies over and sticks to the sweater. View the charges in the sweater, balloons, and the wall.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

Students hypothesize whether vinegar and ammonia-based glass cleaner are acids or bases. They create designs on index cards using these substances as invisible inks. After the index cards have dried, they apply red cabbage juice as an indicator to reveal the designs.

Students learn the basics of acid/base chemistry in a fun, interactive way by studying instances of acid/base chemistry found in popular films such as Harry Potter and the Prisoner of Azkaban and National Treasure. Students learn what acids, bases and indicators are and how they can be used, including invisible ink. They also learn how engineers use acids and bases every day to better our quality of life. Students' interest is piqued by the use of popular culture in the classroom.

Look inside a resistor to see how it works. Increase the battery voltage to make more electrons flow though the resistor. Increase the resistance to block the flow of electrons. Watch the current and resistor temperature change.

Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.

Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.

Students explore the properties of composites using inexpensive materials and processing techniques. They create beams using Laffy Taffy and water, and a choice of various reinforcements (pasta, rice, candies) and fabricating temperatures. Student groups compete for the highest strength beam. They measure flexure strength with three-point bend tests and calculations. Results are compared and discussed to learn how different materials and reinforcement shapes affect material properties and performance.

Lighting is responsible for nearly one-third of the electricity use in buildings. One of the best ways to conserve energy is to make sure the lights are turned off when no one is in a room. This process can be automated using motion sensors. In this activity, students explore material properties as they relate to motion detection, and use that knowledge to make design judgments about what types of motion detectors to use in specific applications.

The PhET project at the University of Colorado creates "fun, interactive, research-based simulations of physical phenomena." This particular one deals with Beer's Law. "The thicker the glass, the darker the brew, the less the light that passes through." Make colorful concentrated and dilute solutions and explore how much light they absorb and transmit using a virtual spectrophotometer! The simulation is also paired with a teachers' guide and related resources from PhET. The simulation is also available in multiple languages.

The study of biomimicry and sustainable design promises great benefits in design applications, offering cost-effective, resourceful, non-polluting avenues for new enterprise. An important final caveat for students to understand is that once copied, species are not expendable. Biomimicry is intended to help people by identifying natural functions from which to pattern human-driven services. Biomimicry was never intended to replace species. Ecosystems remain in critical need of ongoing protection and biodiversity must be preserved for the overall health of the planet. This activity addresses the negative ramifications of species decline. For example, pollinators such as bees are a vital work force in agriculture. They perform an irreplaceable task in ensuring the harvest of most fruit and vegetable crops. In the face of the unexplained colony collapse disorder, we are only now beginning to understand how invaluable these insects are in keeping food costs down and even making the existence of these foods possible for humans.

Explore bending of light between two media with different indices of refraction. See how changing from air to water to glass changes the bending angle. Play with prisms of different shapes and make rainbows.