Assertion : Ozone is an allotrope of oxygen.
Reason : Oxygen is bluish colour liquid and in singlet state it is more paramagnetic.

Options

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

Explanation

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

**Assertion:** Ozone is an allotrope of oxygen.
**Reason:** Oxygen is a bluish color liquid and in singlet state it is more paramagnetic.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- Ozone (O₃) is indeed an allotrope of oxygen. Allotropes are different forms of the same element. Oxygen has several allotropes, including dioxygen (O₂) and ozone (O₃). Thus, the assertion is **true**.

2. **Analyzing the Reason:**
- The reason states that oxygen is a bluish color liquid. This is **true**; liquid oxygen does have a pale blue color.
- The reason also claims that in the singlet state, oxygen is more paramagnetic. To evaluate this, we need to consider the electronic configuration of oxygen.
- Oxygen in its ground state (O₂) has two unpaired electrons, making it paramagnetic. However, in the singlet state, the electrons are paired, resulting in a **diamagnetic** state, not paramagnetic. Therefore, this part of the reason is **false**.

3. **Conclusion:**
- Since the assertion is true and the reason is false, we conclude that the assertion is correct, but the reason does not correctly explain the assertion.

### Final Answer:
- The assertion is true, and the reason is false. Therefore, the correct option is: **Assertion is true, but reason is false.**

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