Educational model for demonstrating intermolecular repulsion and attraction Key benefits Visual and handson demonstration of elastic force: clearly shows how compression produces an elastic restoring force that resists compression, illustrating repulsion between molecules. Simple, focused design: the device uses only plastic balls, a metal spring, and a tightened rubber band to represent molecular interaction without unnecessary complexity. Suitable for teaching and learning: helps students and instructors bridge the gap between abstract molecular concepts and observable mechanical behavior. What it does and how it solves problems Simulates the behavior of molecules under compression and extension by translating molecular forces into observable spring and rubber band mechanics. Makes the concept of intermolecular repulsion intuitive: when the two plastic balls are pushed together, the spring and tightened rubber band produce a measurable restoring force that demonstrates why materials resist compression. Supports active learning and classroom discussion by enabling repeated demonstrations of attraction and repulsion behavior. Product details and attributes Components: two plastic balls, one spring connecting the balls, and one tightened rubber band. Materials: plastic balls, spring, rubber band. Function: models intermolecular repulsion and attraction through spring tension and rubber band tension; compress the assembly to observe the elastic force resisting compression. Compatibility: designed for classroom and laboratory demonstrations in physics and chemistry courses, compatible with tabletop experiment setups and handson teaching activities. Performance: provides a clear, repeatable mechanical demonstration of elastic restoring force and resistance to compression. Use scenarios Classroom demonstration: instructor compresses the model to show students how elastic force rises as molecules are forced closer together, prompting discussion of intermolecular forces. Laboratory exercise: students use the model in small groups to observe and report qualitative relationships between applied compression and the restoring effect produced by the spring and rubber band. Science fair or outreach exhibit: a compact, easytoobserve model that helps communicate basic molecular behavior to general audiences. What makes it stand out Direct physical analogy: the combination of plastic balls, spring, and tightened rubber band creates a straightforward mechanical analogy for molecular repulsion and attraction. Easy to demonstrate and repeat: the simple construction allows quick setup and multiple repetitions during instruction. Contents match the described function and provide a practical, handson way to illustrate why objects resist compression due to intermolecular repulsion.