Which state of matter can be described as having particles that are far apart and moving freely?

The state of matter that is characterized by particles that are far apart and moving freely is gas. In this state, the particles have enough energy to overcome intermolecular forces, allowing them to move independently of each other. This freedom of movement means that gases can expand to fill their container and do not have a fixed shape or volume.

This behavior contrasts with solids, where particles are closely packed and vibrate in place, and liquids, where particles are also close but can slide past one another, giving them a definite volume but not a fixed shape. The term "crystalline" refers specifically to a type of solid in which the particles are arranged in a highly ordered structure, further solidifying the distinction between solids and gases. Thus, gases exemplify the state of matter with particles that are both far apart and in constant motion.