According to the kinetic molecular theory, how does changing the temperature affect the average kinetic energy of gas molecules?

• A. Increasing the temperature increases the average kinetic energy, while decreasing the temperature decreases it.
• B. Increasing the temperature decreases the average kinetic energy, while decreasing the temperature increases it.
• C. Temperature changes do not affect the average kinetic energy of gas molecules.
• D. The average kinetic energy of gas molecules remains constant regardless of temperature.

Answer: (A)

Verified step by step guidance

1. Recall the kinetic molecular theory, which states that the average kinetic energy of gas molecules is directly proportional to the absolute temperature (measured in Kelvin).
2. Express this relationship mathematically as: \(\text{KE}_{\text{avg}} = \frac{3}{2} k_B T\), where \(k_B\) is the Boltzmann constant and \(T\) is the absolute temperature.
3. Understand that when the temperature increases, the value of \(T\) increases, which causes the average kinetic energy \(\text{KE}_{\text{avg}}\) to increase proportionally.
4. Similarly, when the temperature decreases, the value of \(T\) decreases, leading to a proportional decrease in the average kinetic energy of the gas molecules.
5. Conclude that temperature changes directly affect the average kinetic energy of gas molecules: increasing temperature increases kinetic energy, and decreasing temperature decreases kinetic energy.