Which postulate of the kinetic-molecular theory best describes the behavior of particles in a liquid?

• A. Particles are in constant motion and experience intermolecular attractions.
• B. Collisions between particles are perfectly elastic and there is no energy loss.
• C. Particles occupy negligible volume compared to the container.
• D. Particles move in straight lines and do not interact with each other.

Answer: (A)

Verified step by step guidance

1. Recall that the kinetic-molecular theory explains the behavior of particles in different states of matter (solid, liquid, gas) based on their motion and interactions.
2. Identify that in a liquid, particles are close together but still able to move past one another, which means they are in constant motion but also experience forces that keep them somewhat attracted.
3. Understand that the postulate stating 'Particles are in constant motion and experience intermolecular attractions' captures this behavior because it acknowledges both movement and the presence of intermolecular forces.
4. Compare this to other postulates: 'Collisions are perfectly elastic' and 'Particles occupy negligible volume' are more applicable to ideal gases, where particles do not attract each other and have negligible size relative to the container.
5. Recognize that 'Particles move in straight lines and do not interact' also describes ideal gas behavior, not liquids, where interactions are significant.