Final answer:
The key difference between the particles in gases like air and liquids like water is the density and interaction between the particles. Air particles are much farther apart, which allows gases to be easily compressed and spread out to fill containers, while liquid particles are closer together and do not compress easily.
Step-by-step explanation:
The primary difference in the relationships between particles that make up liquids like water and gases like air lies in the spacing and interaction between the particles. Air particles are farther apart compared to water particles, which means there's a significant difference in particle density. Liquids have particles that are closer together and more strongly interacting. Meanwhile, in gases, the particles are much farther apart, leading to weaker intermolecular forces, except when particles collide during motion. This larger separation allows gases to be more easily compressed and to expand rapidly to fill containers, while liquids are not easily compressible and have a definite volume.
Gases and liquids are both considered to be fluids due to their ability to flow; however, their properties are distinct because of their molecular structures. In an open container, gases will escape due to the large separation between molecules, while liquids, having closer molecular proximity, will not.