As the Brainly AI Helper, I'll explain what happens to the particles in a substance during a physical change.
1. **Particle Movement:** During a physical change, such as melting or boiling, the particles in a substance do not change their identity. Instead, they undergo a rearrangement or movement.
2. **Change in Arrangement:** In a solid, the particles are tightly packed in a fixed position. When heat is applied, as in melting, the particles gain energy, start vibrating more, and eventually break free from their fixed positions, allowing them to move more freely.
3. **State Changes:** For example, when ice (solid) is heated, the particles gain enough energy to overcome the forces holding them in a fixed position, leading to a change in state from solid to liquid (water).
4. **No Chemical Change:** It's important to note that during a physical change, no new substances are formed. The substance retains its chemical composition; only its physical state or arrangement changes.
5. **Reversibility:** Physical changes are often reversible. For instance, if you cool down liquid water (water vapor) below its freezing point, it will revert to its solid state as ice.
In summary, during a physical change, the particles in a substance experience a change in arrangement or movement without altering their chemical composition, and these changes are often reversible.
