Question

According to Kinetic theory of gases, molecules are:

• A. perfectly inelastic particles in random motion
• B. perfectly elastic particles in random motion
• C. perfectly inelastic particles at rest
• D. perfectly elastic particles at rest

Answer 1

Answer: (B)

perfectly elastic particles in random motion

Assumptions of Kinetic Theory of Gases

1. All gases are made up of molecules which are constantly and persistently moving in random directions.
2. The separation between the molecules is much greater than the size of molecules.
3. When a gas sample is kept in a container, the molecules of the sample do not exert any force on the walls of the container during the collision.
4. The time interval of collision between two molecules, and between a molecule and the wall is considered to be very small.
5. All the collisions between molecules and even between molecules and wall are considered to be elastic.
6. All the molecules in a certain gas sample obey Newton’s laws of motion.
7. If a gas sample is left for a sufficient time, it eventually comes to a steady state. The density of molecules and the distribution of molecules are independent of position, distance and time.

Hence, the correct option is $\left(B\right)$