In the ideal gas model, intermolecular forces are assumed to be zero except during collisions.

Solution

Physics sir · 4 steps

Between collisions an ideal gas molecule feels no pull or push, so it moves in a straight line.

1. Between collisions. Kinetic theory assumes molecules exert no force on each other while they are apart. With no force acting, each molecule moves in a straight line at constant speed.
2. During collisions. Forces act only at the instant of contact, when two molecules or a molecule and the wall collide. These collisions are perfectly elastic and take negligible time compared with the time between collisions.
3. What it means. With no attraction between molecules, there is no intermolecular potential energy. The internal energy of an ideal gas is purely kinetic, so it depends only on temperature.
4. So. The statement matches a core assumption of the ideal gas model, so it is true.

The idea to keep. Ideal gas means no intermolecular forces except at the instant of an elastic collision. That is why its internal energy is all kinetic and depends on temperature alone.

Answer from the NTA final answer key. Solution by PrepWiser.