According to the kinetic molecular theory, which of the following best describes the average time between collisions of gas molecules at room temperature?

• A. On the order of nanoseconds
• B. On the order of hours
• C. On the order of minutes
• D. On the order of seconds

Answer: (A)

Verified step by step guidance

1. Understand that the kinetic molecular theory describes gas molecules as constantly moving and colliding with each other and the walls of their container.
2. Recognize that the average time between collisions depends on factors such as molecular speed, size, and concentration (pressure and temperature).
3. Recall that at room temperature, gas molecules move very fast (hundreds of meters per second) and are very close together, leading to very frequent collisions.
4. Use the concept that the mean free path (average distance traveled between collisions) divided by the average molecular speed gives the average time between collisions.
5. Know from typical values in kinetic theory that this average time is extremely short, on the order of nanoseconds, reflecting the rapid and frequent collisions of gas molecules.