Which of the following is the wrong statement ?

Options

A. `ONCI` and `ONO^(-)` are not isoelectronic.
B. `O^(3)` molecule is bent
C. Ozone is violet-black in solid state
D. Ozone is diamagnetic gas.

Explanation

To determine which of the statements is wrong, we will analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement:** ONCl and ONO⁻ are isoelectronic.

- **Definition of Isoelectronic:** Isoelectronic species have the same number of electrons.
- **Calculation for ONCl:**
- Oxygen (O) has 8 electrons.
- Nitrogen (N) has 7 electrons.
- Chlorine (Cl) has 17 electrons.
- Total electrons in ONCl = 8 + 7 + 17 = 32 electrons.

- **Calculation for ONO⁻:**
- Oxygen (O) has 8 electrons.
- Nitrogen (N) has 7 electrons.
- The second Oxygen (O) has 8 electrons, and the negative charge (−1) adds 1 electron.
- Total electrons in ONO⁻ = 8 + 7 + 8 + 1 = 24 electrons.

- **Conclusion:** Since ONCl has 32 electrons and ONO⁻ has 24 electrons, they are not isoelectronic. Therefore, this statement is **wrong**.

### Step 2: Analyze Statement 2
**Statement:** O₃ molecule is bent.

- **Structure of O₃ (Ozone):** Ozone has a bent structure due to the presence of lone pairs on the central oxygen atom.
- **Hybridization:** The central oxygen in O₃ is sp² hybridized due to the presence of one double bond and one single bond along with one lone pair.
- **Conclusion:** This statement is **correct**.

### Step 3: Analyze Statement 3
**Statement:** Ozone is violet-black in solid state.

- **Color of Ozone:** Ozone (O₃) in its solid state is indeed a deep violet or dark violet color, which can also be described as violet-black.
- **Conclusion:** This statement is **correct**.

### Step 4: Analyze Statement 4
**Statement:** Ozone is a diamagnetic gas.

- **Magnetism of Ozone:** Ozone does not have any unpaired electrons, which makes it diamagnetic.
- **Comparison with O₂:** O₂ is paramagnetic due to the presence of unpaired electrons.
- **Conclusion:** This statement is **correct**.

### Final Conclusion
After analyzing all statements, we find that:
- **Statement 1** is the wrong statement, as ONCl and ONO⁻ are not isoelectronic.

Thus, the answer is **Statement 1**.

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