Final answer:
Atoms and molecules in different phases of matter have different arrangements and movements. In a solid, they are packed tightly and vibrating in place. In a liquid, they can move past each other. In a gas, they are widely spread apart and move freely.
Step-by-step explanation:
The three phases of matter are solid, liquid, and gas. In a solid, the atoms or molecules are in close contact and held in place. In a liquid, the atoms or molecules are still in contact but can move with respect to each other. In a gas, the atoms or molecules are separated from each other by relatively large distances.
For example, think of water. In the solid phase, water is ice. The water molecules are packed together in a fixed arrangement. In the liquid phase, water is liquid water. The water molecules are still in contact but can flow past each other. In the gas phase, water is steam. The water molecules are widely spread apart and move freely.