Compressibility Concepts: Gases, gas density, compressibility, properties of gases Use the following recommendations to increase and/or decrease the challenge difficulty for your students. Short-on-time Inquiry Lab: Students follow a detailed procedure to observe that gases are more compressible than solids and liquids because the particles in a gas are much farther apart than the particles in a solid or liquid. Guided Inquiry Lab: Students follow a detailed procedure to observe the compressibility of a gas. Students must then determine how to measure the compressibility of a solid and the compressibility of a liquid. Open Inquiry Lab: Students develop a procedure to compare, qualitatively, the compressibilities of the three states of matter: gas, liquid, and solid. The procedure must include a description of which variables are controls, which variables are independent, and which variables are dependent. Advanced Inquiry Lab: Students develop a procedure to compare, qualitatively, the compressibilities of the three states of matter, using water in its three phases. The procedure must include a description of which variables are controls, which variables are independent, and which variables are dependent. Outcomes: Students determine that gases are more compressible than solids and liquids owing to the fact that gas particles spread out in confined spaces and are separated by large interparticle distances. Associated Phenomena: Wind Standards Science & Engineering Practices Disciplinary Core Ideas Crosscutting Concepts Planning and carrying out investigations HS-PS3.A: Definition of Energy Energy and Matter in Systems Analyzing and interpreting data Constructing explanations and designing solutions Performance Expectations HS-PS3-2: Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motions of particles (objects) and energy associated with the relative position of particles (objects)..