Which of the following is the wrong statement?

Options

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

Answer

To determine which of the statements is incorrect, let's analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement:** O and Cl and O and O- are not isoelectronic.

- **Explanation:** Isoelectronic species are those that have the same number of electrons.
- Oxygen (O) has 8 electrons.
- Chlorine (Cl) has 17 electrons.
- O- (the oxide ion) has 9 electrons (8 from O + 1 from the extra electron).

Since O and Cl have different numbers of electrons (8 vs 17), and O and O- also have different numbers of electrons (8 vs 9), this statement is **correct**.

### Step 2: Analyze the second statement
**Statement:** O3 is a bent molecule.

- **Explanation:** Ozone (O3) has a bent molecular geometry due to the presence of a lone pair on the central oxygen atom. The bond angle is approximately 117 degrees, which confirms that this statement is **correct**.

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

- **Explanation:** When ozone is cooled and solidified, it indeed appears as a violet-black solid. This is a known characteristic of solid ozone, making this statement **correct**.

### Step 4: Analyze the fourth statement
**Statement:** Ozone is a paramagnetic gas.

- **Explanation:** Paramagnetic substances have unpaired electrons, while diamagnetic substances have all paired electrons. Ozone (O3) has all its electrons paired in its molecular orbital configuration, making it a diamagnetic gas, not paramagnetic. Therefore, this statement is **incorrect**.

### Conclusion
The wrong statement among the options provided is that "Ozone is a paramagnetic gas."

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