Tag: diffusion in different states of matter

The common unit of measuring volume is litre (L).

Both solids and liquids have a fixed volume but gases do not have a fixed volume. This is because liquids and solids have strong intermolecular forces of attraction compared to gases.

A distinctive property of the liquid state is surface tension, leading to wetting phenomena. Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible. At liquid-air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion).

The top of a liquid will usually have a flat surface. That flat surface is the result of gravity pulling on the liquid molecules. If you put an ice cube (solid) into the cup, it will sit there and not change shape. As the cube warms and melts, the liquid water will fill the bottom of the cup and have a flat surface on top.

Liquids are found between the solid and gas states. A trait of liquids is that they are difficult to compress.

The rate of diffusion of liquids is higher than that of solids. This is due to the fact that in the liquid state, particles move freely and have greater space between each other as compared to particles in the solid state.

Viscosity is a measure of how much a liquid resists flowing freely. Viscosity can usually be reduced by heating the liquid. When heated, the particles of the liquid move faster, allowing the liquid to flow more easily.

Only two elements are liquid at standard conditions for temperature and pressure i.e. mercury and bromine. 

Volatile liquids have low boiling point. As a result, they evaporate very easily at room temperature. Because of their low boiling points, volatile liquids convert to the gas phase at a lower temperature and the gas molecules can diffuse faster than the molecules of a non-volatile liquid.

The density of a liquid is usually close to that of a solid, and much higher than in a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids.