Which one of the following change can be reversed ?

Options

A. water changing into ice
B. nails becoming rusty
C. bread turning mouldy
D. paper burning into ash

Answer

To determine which change can be reversed, we need to analyze the options provided and identify whether they represent physical or chemical changes.

### Step-by-Step Solution:

1. **Understand the Types of Changes**:
- Physical changes are changes that do not alter the chemical composition of a substance. They can be reversed.
- Chemical changes involve a transformation that alters the chemical composition, resulting in new substances. These changes are usually irreversible.

2. **Analyze the First Option**:
- **Water changing into ice**: This is a physical change. When water (liquid) freezes, it becomes ice (solid). If we heat the ice, it melts back into water. This process can be reversed, making it a reversible change.

3. **Analyze the Second Option**:
- **Nails becoming rusty**: This is a chemical change. When iron nails come into contact with air and moisture, they undergo a chemical reaction to form rust (Fe2O3·XH2O). This process creates a new substance, and it cannot be reversed easily, making it an irreversible change.

4. **Conclusion**:
- The only reversible change among the options is **water changing into ice**.

### Final Answer:
The change that can be reversed is **water changing into ice**.

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