How do the three states of matter differ from one another?

The three states of matter—solid, liquid, and gas—differ primarily based on the distance of separation between individual molecules. In solids, molecules are closely packed together in a fixed arrangement, which gives solids a definite shape and volume. In liquids, the molecules are still relatively close but can move past one another, allowing liquids to take the shape of their container while maintaining a constant volume. In gases, the molecules are far apart and move freely, resulting in neither a definite shape nor a defined volume. This fundamental difference in the spacing of molecules underlies the distinct physical properties and behaviors of solids, liquids, and gases. Understanding the molecular arrangement helps explain why matter behaves differently in each state, supporting the selection of the option regarding molecular distance as the key distinguishing factor.