How do gaseous densities differ from solids and liquids?

Gaseous densities are significantly lower than those of solids and liquids due to their widely spaced particles.

In more detail, the density of a substance is determined by the mass of its particles and the space they occupy. In solids, particles are tightly packed together, occupying minimal space, which results in high density. Liquids also have relatively high densities as their particles are close together, though not as tightly packed as in solids.

Gases, on the other hand, have particles that are widely spaced apart. This is due to the high kinetic energy of gas particles, which allows them to move freely and occupy a larger volume. This large volume, in relation to the mass of the gas particles, results in a significantly lower density compared to solids and liquids.

Furthermore, the densities of gases are more susceptible to changes in temperature and pressure. When a gas is heated, its particles gain more kinetic energy and move further apart, increasing the volume and hence decreasing the density. Similarly, when the pressure on a gas is increased, its volume decreases and the density increases. This behaviour is unique to gases and is described by the ideal gas law.

In contrast, the densities of solids and liquids are relatively unaffected by changes in temperature and pressure. This is because the particles in solids and liquids are already so close together that changes in temperature or pressure have little effect on their spacing.

In summary, the lower density of gases compared to solids and liquids is due to the large volume occupied by their widely spaced particles, and their densities are more affected by changes in temperature and pressure.