How does the temperature of compressed air change?

When air is compressed, its temperature increases due to the principles of thermodynamics. This phenomenon is primarily explained by the ideal gas law, which states that when the volume of gas decreases and the amount of gas remains constant, the pressure increases. As the pressure increases, the kinetic energy of the air molecules also increases, which in turn raises the temperature of the air.

This is further illustrated by the concept of adiabatic compression, where no heat is lost to the surroundings during the compression process. The work done on the gas during compression results in an increase in thermal energy, leading to a rise in temperature.

Thus, when compressed, air experiences a rise in temperature, making it clear that the correct answer is that the temperature increases.