What happens to the energy of particles when a substance freezes?

The correct answer is Energy decreases and particles move slower.

Unit lens: Check the units before giving the final statement so the physics quantity is not swapped. This question asks: What happens to the energy of particles when a substance freezes. The correct response is Energy decreases and particles move slower, because changes of state are explained by particle energy and arrangement. In Changes of state, the marking point should connect directly to explain freezing using decreased particle energy and changed particle arrangement. 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 133 is distinct because it uses this exact question context and the unit lens rather than a generic particle-model sentence.