States of Matter

Overview

Matter is anything that has mass and takes up space. It exists in different physical forms known as states of matter. The most common states of matter are solid, liquid, and gas.

Solid

A solid has a definite shape and volume. The particles in a solid are closely packed and vibrate in fixed positions. They have strong attractive forces between them, which is why solids maintain their shape.

Liquid

Liquids have a definite volume but take the shape of their container. The particles in a liquid are still close together but can move past each other, allowing the liquid to flow.

Gas

Gases have neither a definite shape nor a definite volume. The particles in a gas are far apart and move freely, colliding with each other and the walls of their container. This is why gases expand to fill their container.

Changes of State

Matter can change from one state to another through processes such as melting, freezing, evaporation, condensation, and sublimation.

Plasma and Bose-Einstein Condensate

Besides the three common states, there are two other states of matter: plasma, which exists at very high temperatures and consists of ionized particles, and Bose-Einstein condensate, which occurs at extremely low temperatures.

Study Tips

1. Understand the arrangement and behavior of particles in each state of matter.
2. Memorize the temperature and pressure conditions at which substances change states.
3. Practice identifying examples of each state of matter in everyday life.
4. Review the unique properties of plasma and Bose-Einstein condensate.