Question

Which statement best describes the collisions of gas particles according to the kinetic-molecular theory?
When particles pass close enough to one another, their attractions pull them together, and then they bounce apart with no gain or loss of energy.
As particles travel in straight lines, their paths sometimes meet, and then they bounce apart with no gain or loss of energy.
When particles pass close enough to one another, their attractions pull them together, and then they bounce apart with a loss of energy.
As particles travel in straight lines, their paths sometimes meet, and then they bounce apart with a loss of energy.

Answer 1

"As particles travel in straight lines, their paths sometimes meet, and then they bounce apart with no gain or loss of energy."

Kinetic‑molecular theory assumes gas particles move in straight lines between collisions and that collisions are elastic (no net kinetic energy lost).