Which of the following best describes an ideal gas?

An ideal gas is defined as a hypothetical gas that perfectly follows the ideal gas law, which states that the pressure, volume, and temperature relationships are consistent under all conditions. The characteristics of an ideal gas include particles that occupy no volume, are in constant random motion, and do not interact with each other except during elastic collisions. This theoretical concept is useful in simplifying calculations and understanding gas behavior under varying conditions.

Under real-life conditions, no gas exhibits this behavior perfectly, as they can deviate from these ideal conditions due to intermolecular forces and the volume occupied by gas molecules. However, the best description of an ideal gas is one that behaves perfectly under all conditions, as it serves as a reference for comparing real gases.