Phases of matter

Science

Definition

Matter exists primarily in three phases: solid (fixed shape and volume, particles tightly packed), liquid (fixed volume but takes shape of container, particles close but mobile), and gas (no fixed shape or volume, particles widely spaced and fast-moving). Plasma is a fourth phase consisting of ionized gas.

Examples

  • Ice melting into liquid water at 0°C and boiling into steam at 100°C
  • Dry ice (solid CO₂) sublimating directly into gas at room pressure
  • Lightning creating plasma by ionizing air molecules

Related Terms

Phase diagrams Water properties Kinetic energy Enthalpy

Study This Concept

Practice phases of matter with free review games in these units:

Chemistry Unit 6: States of Matter and Gas Laws