• 6-8: 4D/M1a. All matter is made up of atoms, which are far too small to see directly through a microscope.
• 6-8: 4D/M2. Equal volumes of different materials usually have different masses.
• 6-8: 4D/M3cd. In solids, the atoms or molecules are closely locked in position and can only vibrate. In liquids, they have higher energy, are more loosely connected, and can slide past one another; some molecules may get enough energy to escape into a gas. In gases, the atoms or molecules have still more energy and are free of one another except during occasional collisions.
• 6-8: 4D/M7a. No matter how substances within a closed system interact with one another, or how they combine or break apart, the total mass of the system remains the same.
• 6-8: 4D/M8. Most substances can exist as a solid, liquid, or gas depending on temperature.

• 6-8: 4E/M4. Energy appears in different forms and can be transformed within a system. Motion energy is associated with the speed of an object. Thermal energy is associated with the temperature of an object. Gravitational energy is associated with the height of an object above a reference point. Elastic energy is associated with the stretching or compressing of an elastic object. Chemical energy is associated with the composition of a substance. Electrical energy is associated with an electric current in a circuit. Light energy is associated with the frequency of electromagnetic waves.
• 9-12: 4E/H7. Thermal energy in a system is associated with the disordered motions of its atoms or molecules. Gravitational energy is associated with the separation of mutually attracting masses. Electrical potential energy is associated with the separation of mutually attracting or repelling charges.
• 9-12: 4E/H9. Many forms of energy can be considered to be either kinetic energy, which is the energy of motion, or potential energy, which depends on the separation between mutually attracting or repelling objects.

• 9-12: 4G/H2a. Electric forces acting within and between atoms are vastly stronger than the gravitational forces acting between the atoms. At larger scales, gravitational forces accumulate to produce a large and noticeable effect, whereas electric forces tend to cancel each other out.

• 6-8: 11B/M1. Models are often used to think about processes that happen too slowly, too quickly, or on too small a scale to observe directly. They are also used for processes that are too vast, too complex, or too dangerous to study.
• 6-8: 11B/M4. Simulations are often useful in modeling events and processes.

• 6-8: 11D/M3. Natural phenomena often involve sizes, durations, and speeds that are extremely small or extremely large. These phenomena may be difficult to appreciate because they involve magnitudes far outside human experience.

This simulation can help students visualize how molecules behave in solids, liquids, and gases. Add or remove heat and watch the motion of the molecules as they change phase. Push the pump and change the volume of matter in the closed container. More advanced students can compare the potential energy graphs for neon, argon, oxygen, and water (which all have different interaction potential).

• Physical Sciences K-8 Matter and Interactions Unit
• Physics First Matter and Interactions Unit
• Conceptual Physics Matter and Interactions Unit
• Algebra-Based Physics Matter and Interactions Unit
• AP/Calculus-Based Physics Matter and Interactions Unit

Great simulation to promote understanding of how molecules behave in solids, liquids, and gases. Add or remove heat and watch the motion of the molecules as they change phase. Push the pump and change the volume of matter in the closed container and watch the pressure gauge respond. More advanced students can compare the potential energy graphs for neon, argon, oxygen, and water -- which all have different interaction potential. For detailed Student Guide, see the item directly above.

• Physics First Teaching about Heat and Thermal Energy Unit
• Conceptual Physics Teaching about Heat and Thermal Energy Unit
• Algebra-Based Physics Teaching about Heat and Thermal Energy Unit
• AP/Calculus-Based Physics Teaching about Heat and Thermal Energy Unit