Matter exists in three primary states: Solid, Liquid, and Gas. The state of matter depends on the arrangement and energy of the particles.
In a solid, particles are closely packed together and vibrate in place. Solids have a fixed shape and volume because the particles are not free to move around.
In a liquid, particles are still closely packed, but they are free to move around. Liquids have a fixed volume but no fixed shape; they take the shape of the container they are in.
In a gas, particles are spread far apart and move freely. Gases have neither a fixed shape nor a fixed volume; they expand to fill any container.
Click the button to see how the particles move in a solid, liquid, and gas.
1. In which state of matter do particles vibrate but do not move freely?
2. Which state of matter has particles that are spread far apart and move freely?
3. In which state of matter do particles move around but are still close to each other?
4. What happens to the particles of a substance when it is heated?
5. Which state of matter has a definite volume but no definite shape?