The ion that is isoelectronic with CO is -

Options

A. NO
B. `N_2`
C. `C_2`
D. `F_2`

Answer

To determine the ion that is isoelectronic with carbon monoxide (CO), we need to follow these steps:

### Step 1: Calculate the total number of electrons in CO
- Carbon (C) has 6 electrons.
- Oxygen (O) has 8 electrons.
- Therefore, the total number of electrons in CO = 6 (from C) + 8 (from O) = 14 electrons.

### Step 2: Identify the isoelectronic species
An isoelectronic species has the same number of electrons as CO, which is 14. We will check various ions to see which one has 14 electrons.

### Step 3: Check the options
1. **Nitrogen (N)**:
- Nitrogen has 7 electrons.
- If we consider the ion N²⁻ (which has gained 2 electrons), it will have 7 + 2 = 9 electrons. This does not match.
- For N⁺ (which has lost 1 electron), it will have 7 - 1 = 6 electrons. This does not match.
- For N, it has 7 electrons. Therefore, N alone does not match.

2. **Oxygen (O)**:
- Oxygen has 8 electrons.
- If we consider O²⁻ (which has gained 2 electrons), it will have 8 + 2 = 10 electrons. This does not match.
- For O⁻ (which has gained 1 electron), it will have 8 + 1 = 9 electrons. This does not match.
- For O, it has 8 electrons. Therefore, O alone does not match.

3. **Fluorine (F)**:
- Fluorine has 9 electrons.
- If we consider F⁻ (which has gained 1 electron), it will have 9 + 1 = 10 electrons. This does not match.
- For F, it has 9 electrons. Therefore, F alone does not match.

4. **Nitric Oxide (NO)**:
- Nitrogen has 7 electrons and Oxygen has 8 electrons.
- Therefore, NO has 7 + 8 = 15 electrons. This does not match.

5. **Carbon Dioxide (CO₂)**:
- Carbon has 6 electrons and each Oxygen has 8 electrons.
- Therefore, CO₂ has 6 + 8 + 8 = 22 electrons. This does not match.

6. **N₂ (Diatomic Nitrogen)**:
- Each Nitrogen atom has 7 electrons.
- Therefore, N₂ has 7 + 7 = 14 electrons. This matches.

### Conclusion
The ion that is isoelectronic with CO is N₂ (Diatomic Nitrogen).

### Final Answer
The ion that is isoelectronic with CO is **N₂**.