A change in temperature from 20 to 30 °C is most closely associated with an increase in the average kinetic energy of the molecules of a sample of N2(g).
The average kinetic energy of gas molecules is directly proportional to their temperature, as described by the kinetic theory of gases. In this context, a change in temperature from 20 to 30 °C corresponds to an increase in the average kinetic energy of the nitrogen gas (N₂) molecules. Temperature is a measure of the average translational kinetic energy of the particles in a system, and as it rises, the molecules gain more energy and move with higher velocities.
The other options—changes in pressure, volume, or temperature in different ranges—also influence gas behavior but are not as directly associated with the average kinetic energy of the molecules as changes in temperature. Therefore, the most closely associated change with an increase in average kinetic energy is a change in temperature from 20 to 30 °C.