Matter" refers to anything that has mass and occupies space. It is the substance of which all physical objects are composed. Matter can exist in various states, each characterized by its physical properties and arrangement of particles. The three primary states of matter are solid, liquid, and gas. States of Matter: Solid: Solids have a definite shape and volume. The particles in a solid are closely packed together in a regular arrangement. The particles vibrate in place but do not move past each other easily. Examples include ice, wood, metal, and rocks. Liquid: Liquids have a definite volume but take the shape of their container. The particles in a liquid are still close together but are not in a fixed position. They can move past each other, allowing liquids to flow. Examples include water, oil, milk, and juice. Gas: Gases have neither a definite shape nor volume. The particles in a gas