Assertion :- In Meselson and Stahl experiment `""^(15)NH_(4)Cl` can be separated from `""^(14)N ` by radiography.
Reason : In `""^(15)NH_(4)Cl,""^(15)N` is a radioactive isotope.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are trur but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is Flase.
D. If both Assertion & Reason are false.

Answer

To solve the assertion and reason question regarding the Meselson and Stahl experiment, we will analyze both the assertion and the reason step by step.

### Step 1: Analyze the Assertion
The assertion states: "In Meselson and Stahl experiment, \(^{15}NH_4Cl\) can be separated from \(^{14}N\) by radiography."

- **Explanation**: The Meselson and Stahl experiment was designed to demonstrate the semi-conservative replication of DNA using isotopes of nitrogen. They used \(^{15}N\) (heavy nitrogen) and \(^{14}N\) (light nitrogen) to label the DNA in E. coli. However, the separation of these isotopes was not achieved through radiography. Instead, they used a technique called density gradient centrifugation to separate the DNA based on the density differences caused by the isotopes.

**Conclusion**: The assertion is **false** because \(^{15}NH_4Cl\) cannot be separated from \(^{14}N\) by radiography.

### Step 2: Analyze the Reason
The reason states: "In \(^{15}NH_4Cl\), \(^{15}N\) is a radioactive isotope."

- **Explanation**: \(^{15}N\) is indeed an isotope of nitrogen, but it is not radioactive. It is a stable isotope and does not emit radiation. The confusion may arise from the fact that isotopes can be either stable or radioactive, but in this case, \(^{15}N\) is stable.

**Conclusion**: The reason is **false** because \(^{15}N\) is not a radioactive isotope.

### Final Conclusion
Both the assertion and the reason are false. Therefore, the correct answer to the question is that both statements are incorrect.

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