Assertion :- All diamagnetic species are colourless
Reason :- All paramagnetic species are colourful.

Options

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

Answer

To solve the question, we need to analyze the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that "All diamagnetic species are colorless."
- **Diamagnetic species** are those that do not have unpaired electrons. They are generally not affected by magnetic fields and do not exhibit color due to the absence of d-d transitions (which are responsible for color in transition metals).

### Step 2: Understand the Reason
The reason states that "All paramagnetic species are colorful."
- **Paramagnetic species** have unpaired electrons and can exhibit color due to d-d transitions. These transitions occur when electrons move between different energy levels in the presence of light, which can lead to the absorption of certain wavelengths and thus the appearance of color.

### Step 3: Evaluate the Truth of Each Statement
- The assertion is **false** because not all diamagnetic species are colorless. Some can exhibit color under certain conditions.
- The reason is also **false** because not all paramagnetic species are colorful. Some may not absorb visible light or may not have transitions that result in color.

### Step 4: Conclusion
Since both the assertion and the reason are false, the correct answer is that both A and R are false.

### Final Answer
Both the assertion and the reason are false.

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