Ideal Gas Model and Molecular Motion

The ideal-gas model makes molecular behaviour easier to analyse. Gas contains a very large number of molecules. Molecules move continuously and randomly. Their own volume is negligible compared with the container volume. Intermolecular forces are neglected except during collisions. Collisions between molecules and container walls are treated as elastic. Molecules obey classical mechanics in the basic model.

Real gases are complicated. The ideal model removes unnecessary detail while retaining the behaviour needed to explain many gas properties. It works particularly well when gases are sufficiently dilute.

**pV = NkT** where: `N` = number of molecules `k` = Boltzmann constant `T` = absolute temperature