NCCER Millwright Practice Exam

Which property of a gas is directly affected by temperature changes?

1. Density

2. Viscosity

3. Pressure

4. Kinetic energy

The correct answer is: Kinetic energy

The kinetic energy of a gas is directly affected by temperature changes because temperature is a measure of the average kinetic energy of the molecules in a substance. As the temperature increases, the kinetic energy of the gas molecules also increases, causing them to move faster. This higher speed results in more energetic collisions among the molecules and with the walls of their container, leading to various effects in the gas's behavior, such as increased pressure if the volume is kept constant. When temperature decreases, the kinetic energy of the molecules diminishes, causing them to move more slowly and reducing the energy of their collisions. This fundamental relationship is essential in understanding gas laws and the behavior of gases under varying thermal conditions. Thus, temperature is a critical factor influencing the kinetic energy of a gas, making it the correct choice in this context.