A: `Ce^(+4)` is a good oxidizing agent.
R: `Sm^(2+)` is a good reducing agent

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To analyze the assertion and reason provided in the question, we will break down the statements regarding cerium (Ce) and samarium (Sm) step by step.

### Step 1: Analyze the Assertion
**Assertion:** Ce^(+4) is a good oxidizing agent.

- **Explanation:**
- Cerium (Ce) has the electronic configuration of [Xe] 4f^1 5d^1 6s^2.
- In its +4 oxidation state (Ce^(+4)), cerium can lose an additional electron from its 5d or 6s orbitals, which allows it to achieve a more stable +3 oxidation state (Ce^(+3)).
- The ability to accept electrons (by being reduced to Ce^(+3)) makes Ce^(+4) a good oxidizing agent.

### Step 2: Analyze the Reason
**Reason:** Sm^(2+) is a good reducing agent.

- **Explanation:**
- Samarium (Sm) is a lanthanide with an electronic configuration of [Xe] 4f^6 6s^2.
- In its +2 oxidation state (Sm^(2+)), samarium can easily lose an electron to achieve the more stable +3 oxidation state (Sm^(+3)).
- This tendency to lose electrons and be oxidized makes Sm^(2+) a good reducing agent.

### Step 3: Conclusion
- Both the assertion and reason are true statements.
- However, the reason provided does not correctly explain why Ce^(+4) is a good oxidizing agent. The reason pertains to the properties of Sm^(2+) rather than directly relating to the oxidizing ability of Ce^(+4).

### Final Answer
- Therefore, the correct conclusion is that both the assertion and reason are true, but the reason is not a correct explanation of the assertion. This corresponds to option B.

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