The physical state characterized by the absence of a fixed volume and the inability to maintain a specific form is a phase of matter where constituent particles are widely dispersed and exhibit negligible intermolecular forces. Air, as a mixture of gases, exemplifies this state, readily expanding to fill any available space and conforming to the shape of its container.
Understanding this particular phase is fundamental in various scientific and engineering disciplines. Its behavior dictates the principles of thermodynamics, fluid dynamics, and atmospheric science. Historically, the study of these properties has led to advancements in technologies ranging from internal combustion engines to weather forecasting models. The ability to manipulate and predict its behavior is crucial for efficient energy production and climate change mitigation.