What allows liquids to flow according to the particle model?

The correct answer is Particles are loosely packed and can slide past each other..

Particle lens: Describe arrangement, motion, spacing, collisions, or energy changes only when they are relevant here. This question asks: What allows liquids to flow according to the particle model. The correct response is Particles are loosely packed and can slide past each other., because gas pressure comes from particle collisions with container walls. In Changes of state, the marking point should connect directly to use the particle model to explain why solids have fixed shapes and liquids and gases flow. If the question includes values, the working must keep the appropriate unit and operation; if it is an explanation, it must name the relevant particle behaviour or energy change. This item belongs to Changes of state and the particle model, so avoid answers that switch to a different quantity, confuse heat with temperature, or describe gas pressure without collisions when collisions are the reason. Checkpoint 192 is distinct because it uses this exact question context and the particle lens rather than a generic particle-model sentence.