Carefully observe changes in kinetic and potential energy as hydrogen and oxygen molecules react.

The MC1R gene, in part, controls deer mouse fur. Two alleles, RD and RL, in different combinations lead to light, medium, or dark brown fur. Students learn how to calculate relative allele frequencies, and then investigate how these frequencies may change over time as the environment in which the deer mice live changes. The activity is divided into four steps, which guide students to a deeper understanding of how evolution is measured.

Explore different types of attractions between molecules. While all molecules are attracted to each other, some attractions are stronger than others. Non-polar molecules are attracted through a London dispersion attraction; polar molecules are attracted through both the London dispersion force and the stronger dipole-dipole attraction. The dipole-dipole attraction is often thought of as 'opposite charges attract; like charges repel.' The force of attractions between molecules has consequences for their interactions in physical, chemical and biological applications.

Explore the pattern of earthquakes on Earth, including magnitude, depth, location, and frequency.

Two linear equations, with two variables, are presented and students use graphs to solve the system of equations. Students graph the lines and solve the problem using the graphs.

Explore the factors that affect a spring's motion. A spring is a resilient device that can be pressed or pulled but return to its original shape when released. Springs are commonly helical coiled metal devices. When a spring is compressed or stretched and then released, it will vibrate at a particular frequency. This frequency is called the period of the spring. Experiment by changing the spring constant (a measure of the elasticity of the coils), the mass of the weight at the end of the spring, the initial extension or compression of the spring or the friction (or damping force) exerted on the spring. Which of these factors affect the period of the spring?

Explore the movement of gases, liquids and solids at a molecular level, and investigate how temperature and intermolecular attractions affect phase changes.

Stebbins is a game about evolution. Students collect data as predators "eating" colored circles on a colored background, being careful to avoid the poisonous ones. Data analysis reveals how the population changes color over time, and can be used to illuminate a common misconception that individuals change in response to predation. Stebbins is modeled on a non-digital game-like simulation of natural selection created by evolutionary biologist G. Ledyard Stebbins.

In Stella, students act as astronomers, studying stars in a "patch" of sky in our own galaxy. Using simulated data from spectroscopy and other real-world instrumentation, students learn to determine star positions, radial velocity, proper motion, and ultimately, degree of parallax. As students establish their expertise in each area, they earn "badges" that allow them greater and easier access to the data.

Explore the interactions between a charged balloon and a neutral wall at the atomic-level.

Map the probable locations of electrons around a nucleus to understand probability distributions and the electron cloud model.

How does solar radiation interact with the Earth and its atmosphere to cause global warming? Use this model to see what's going on at the molecular level. Watch the effects of sunlight and then watch the effects of infrared radiation, also known as heat radiation, on the ground and on carbon dioxide, a greenhouse gas.

Students explore two real-life scenarios that involve solving systems of equations. The first situation involves mixing chemicals to create a new solution while the second situation involves cost and revenue for a bake sale. Exploring these situations allows students to see a real-world connection with mathematics. By the end of this lesson, students will have a greater understanding of how using mathematics to model a real-life situation with two variables can help them solve problems.

Students explore two new scenarios that involve solving systems of equations. The first situation involves the travel time for a round trip on an airplane, while the second situation involves calculating the numbers of students and adults attending a high school musical. By the end of this lesson, students will improve their understanding of how using mathematics to model a real-life situation with two variables can help them solve problems.

Manipulate the magnitude of charges on two objects to get a third positively charged particle to hit a target.

Drag the location of charges to get a positively charged particle to the target while observing forces and fields.

Manipulate the location and magnitude of charges to get a positively charged particle to hit a target.

Explore the relationship between the temperature of a gas and the pressure it exerts on its container. This is commonly known as Gay-Lussac's Law or Amontons' Law of Pressure-Temperature. As the temperature of a gas increases, the pressure it exerts on its container will increase.

Explore the relationship between the temperature of a gas and its volume. This is commonly known as Charles's Law. The volume of a gas tends to increase as the temperature increases.

The transition from a solid to a liquid state is called melting. The transition from a liquid to a gas state is called boiling. The temperatures at which particles change state are important properties of substances. Explore why different substances have different melting and boiling points, then create a rule that relates particle attraction to melting and boiling point.