The phase of matter depends on what?

Answer 1

Heat and pressure are the two main factors that determine a substance's current phase.

With high heat a substance's phase drifts toward the gaseous phase while freezing temperatures cause it to move toward its solid phase. With pressure it is the opposite. Higher pressures push the substance toward its solid phase, while lower pressures will encourage the substance to evaporate into its gaseous phase.

Answer 2

The phase of matter depends on the arrangement and movement of its particles. In solids, particles are tightly packed and vibrate in place. In liquids, particles are more spread out and can move past each other. In gases, particles are far apart and move freely.