Law of conservation of mass is not correct for

Options

A. radloactive change
B. oxidation
C. hydrolysis
D. None of these

Explanation

To solve the question "Law of conservation of mass is not correct for," we need to analyze the options provided and understand the contexts in which the law of conservation of mass may not hold true.

### Step-by-Step Solution:

1. **Understanding the Law of Conservation of Mass**:
- The law states that in a closed system, the mass of the reactants must equal the mass of the products in a chemical reaction. This means that matter cannot be created or destroyed in an isolated system.

2. **Analyzing the Options**:
- **Option 1: Radioactive Change**: In radioactive decay, unstable nuclei lose energy by emitting radiation. During this process, a small amount of mass is converted into energy (as per Einstein's equation E=mc²). This means that the total mass before and after the decay does not remain constant, violating the conservation of mass.

- **Option 2: Oxidation**: Oxidation is a chemical reaction where a substance combines with oxygen. The law of conservation of mass holds true in oxidation reactions as the total mass of the reactants equals the total mass of the products.

- **Option 3: Hydrolysis**: Hydrolysis is a reaction involving water, where a compound reacts with water to form two or more products. The law of conservation of mass also holds true in hydrolysis as the mass of the reactants equals the mass of the products.

- **Option 4: None of These**: This option implies that the law of conservation of mass is valid for all the given processes, which is incorrect since we have established that it does not hold for radioactive changes.

3. **Conclusion**:
- Based on the analysis, the law of conservation of mass is not correct for **radioactive change**. Therefore, the correct answer is **Option 1: Radioactive Change**.

### Final Answer:
The law of conservation of mass is not correct for **radioactive change**.