Assertion : Chlorine has higher electron affinity than fluorine.
Reason : Chlorine is a poor oxidising agent than fluorine.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false
D. If the assertion and reason both are false.

Explanation

To analyze the assertion and reason provided in the question, we will break down the concepts of electron affinity and oxidizing agents step by step.

### Step 1: Understanding Electron Affinity
- **Definition**: Electron affinity is the amount of energy released when an atom in the gas phase accepts an electron to form a negative ion.
- **Trend in the Periodic Table**: Generally, as you move from left to right across a period, electron affinity increases. However, there are exceptions due to atomic size and electron-electron repulsion.

### Step 2: Comparing Electron Affinity of Chlorine and Fluorine
- **Fluorine**: Fluorine has a very small atomic radius, which means that its electrons are held tightly by the nucleus. When an additional electron is added, there is significant electron-electron repulsion among the electrons in the small volume, making it less favorable for fluorine to gain an electron.
- **Chlorine**: Chlorine, being larger in size, has a more spacious electron cloud. The addition of an electron does not face as much repulsion as in fluorine, thus chlorine can stabilize the added electron more effectively.
- **Conclusion**: Chlorine has a higher electron affinity than fluorine, which contradicts the assertion. Therefore, the assertion is **false**.

### Step 3: Understanding Oxidizing Agents
- **Definition**: An oxidizing agent is a substance that gains electrons in a chemical reaction and is reduced in the process.
- **Comparison of Chlorine and Fluorine**: Fluorine is a stronger oxidizing agent than chlorine due to its high electronegativity and ability to attract electrons more effectively.

### Step 4: Analyzing the Reason
- The reason states that chlorine is a poorer oxidizing agent than fluorine. This is **true** because fluorine is indeed a stronger oxidizing agent due to its higher electronegativity and smaller size, which allows it to attract electrons more effectively.

### Step 5: Conclusion
- **Assertion**: Chlorine has higher electron affinity than fluorine. (False)
- **Reason**: Chlorine is a poor oxidizing agent than fluorine. (True)
- Since the assertion is false and the reason is true, the two statements are not connected.

### Final Answer
- Both the assertion and reason are true, but the reason does not explain the assertion. Therefore, the correct option is that the assertion is false, and the reason is true.