2. In paragraphs \( 2-4 \), you read about examples of physical changes. How melting water and crushing ice both be examples of physical changes?

Melting water and crushing ice are both examples of physical changes because they involve alterations in the state or form of a substance without changing its chemical composition. 1. **Melting Water**: When ice melts, it transitions from a solid state to a liquid state. This change occurs when heat is applied, causing the ice molecules to gain energy and move more freely. Despite this change in state, the chemical composition of water (H₂O) remains the same before and after melting. The process is reversible; if the water is cooled, it can freeze back into ice. 2. **Crushing Ice**: Crushing ice involves breaking the solid ice into smaller pieces. This physical change alters the size and shape of the ice but does not change its chemical structure. The ice remains H₂O, and like melting, this process is also reversible; the crushed ice can be recombined into larger pieces if allowed to freeze again. In summary, both melting water and crushing ice are physical changes because they involve changes in physical state or form while maintaining the same chemical identity of the substance.