Which of the following statements explain why the pressure of a gas in an isolated container (with a fixed volume) can increase over time at constant temperature?

• A. The gas decomposes such that there are more gaseous products than reactants.
• B. The average kinetic energy of the gas increases.
• C. The attractive forces of gas molecules increases.
• D. The gas molecules lose energy upon colliding with each other.

Answer: (A)