The particles are moving so if you had a liquid and it physically changed to a solid the liquid particles would be spread out and moving more rapidly but since its changing to a solid in theory the particles would begin to become more compacted and tightly together causing them to not move as much and the particles come closer together.
Sample Response: When a physical change occurs, the arrangement of particles within the substance may change, but the atoms in the molecules remain bonded together. I promise that's the right answer its literally the sample response.
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