Liquids and gases, unlike solids, have the ability to flow and take the shape of their container. This property, known as fluidity, allows liquids and gases to move and conform to the shape of their surroundings.

Liquids have a fixed volume but no definite shape, while gases have neither a fixed volume nor a definite shape. Both liquids and gases can easily flow past solid objects and through small openings. In contrast, solids have a rigid structure and a fixed shape, and they cannot flow or deform easily.

Liquids and gases can also undergo diffusion, which is the movement of particles from an area of higher concentration to an area of lower concentration. This process occurs naturally in both liquids and gases, allowing them to mix and spread out evenly. Diffusion is much slower in solids because the particles are more tightly packed and have less freedom to move.

Liquids and gases also exhibit surface tension, which is the tendency of a liquid or gas to minimize its surface area. This effect can be observed in the formation of soap bubbles and water droplets, where the surface of the liquid or gas forms a thin, elastic membrane to minimize its area. Surface tension is relatively weak in solids and does not play a significant role in their behavior.

The fluidity, diffusion, and surface tension properties of liquids and gases distinguish them from solids and give them unique characteristics that are essential for numerous natural and industrial processes.