In which state of matter do particles move freely without any structure?

Particles in a gas state exhibit high kinetic energy and move freely without being held in a fixed structure, allowing them to spread out and fill any container they occupy. In this state, the intermolecular forces are minimal, which enables particles to move independently of one another, leading to a high degree of disorder. This contrasts with solids, where particles are closely packed in a structured arrangement and can only vibrate in place, and liquids, where particles are close together but can flow past one another, maintaining a definite volume but not a fixed shape. Plasma, while also consisting of freely moving particles, involves ionized gas where electrons are separated from nuclei, but the question specifically pertains to the state where the structure is not maintained, emphasizing the nature of particle movement in gases as the most fitting choice.