Final answer:
The relationship between the observable properties of states of matter and particle structure is explained by the closeness and arrangement of particles in solids, the somewhat freer movement of particles in liquids, and the independent, widely spaced particles in gases.
Step-by-step explanation:
The observable properties of solids, liquids, and gases are directly related to the unobservable structure of particles. Solids are characterized by particles that are closely packed in a fixed arrangement, giving them a fixed volume and shape. Liquids have particles that are still close but can move past one another, meaning they maintain a fixed volume but not a fixed shape. In gases, the particles are much further apart and move freely, resulting in no fixed volume or shape, and an ability to expand indefinitely to fill any container.
Gases are unique among the states of matter in that they can display predictable physical properties regardless of the gas type. This is explained by the kinetic molecular theory, which also accounts for the behavior of liquids and solids by considering particle volume and intermolecular forces. Examples include the compressibility of gases, the fluidity of liquids, and the rigidity of solids.
Understanding the arrangement of atoms in each state is key to explaining their physical characteristics. The kinetic molecular theory offers insights into these differences, explaining properties like density, compressibility, and the capacity to diffuse in terms of the distance between particles and the strength of the forces acting upon them.