Question: 7. Students create a table that lists processes observed in nature.
Process Change
1 Fungus decomposing organic matter
2 Leaves using carbon dioxide to make sugar
3 Plants using nitrogen to make protein
4 Water evaporating from salt water
Which process describes only a physical change?
A. Process 1
B. Process 2
C. Process 3
D. Process 4
1. **State the problem:** We need to identify which process from the table describes only a physical change.
2. **Recall definitions:**
- A **physical change** affects the form of a substance but not its chemical composition.
- A **chemical change** results in the formation of new substances with different properties.
3. **Analyze each process:**
- Process 1: Fungus decomposing organic matter involves breaking down substances chemically, so it is a chemical change.
- Process 2: Leaves using carbon dioxide to make sugar is photosynthesis, a chemical change creating new compounds.
- Process 3: Plants using nitrogen to make protein is a chemical synthesis, so chemical change.
- Process 4: Water evaporating from salt water is a phase change (liquid to gas), which is a physical change because the chemical composition of water remains the same.
4. **Conclusion:**
Only Process 4 describes a physical change.
**Final answer:** D. Process 4