CO is isoelectronic with

Options

A. `NH_3`
B. `N_2`
C. `O_2`
D. `NO_2`.

Answer

To determine which species is isoelectronic with carbon monoxide (CO), we need to follow these steps:

### Step 1: Define Isoelectronic Species
Isoelectronic species are atoms, ions, or molecules that have the same number of electrons.

### Step 2: Calculate the Total Number of Electrons in CO
- Carbon (C) has an atomic number of 6, meaning it has 6 electrons.
- Oxygen (O) has an atomic number of 8, meaning it has 8 electrons.
- Therefore, the total number of electrons in CO is:
\[ \text{Total electrons in CO} = 6 + 8 = 14 \]

### Step 3: Calculate the Total Number of Electrons in Each Option
1. **Ammonia (NH₃)**:
- Nitrogen (N) has 7 electrons.
- Each hydrogen (H) has 1 electron, and there are 3 hydrogens.
- Total electrons in NH₃:
\[ 7 + (3 \times 1) = 7 + 3 = 10 \]

2. **Nitrogen (N₂)**:
- Each nitrogen atom has 7 electrons, and there are 2 nitrogen atoms.
- Total electrons in N₂:
\[ 7 + 7 = 14 \]

3. **Oxygen (O₂)**:
- Each oxygen atom has 8 electrons, and there are 2 oxygen atoms.
- Total electrons in O₂:
\[ 8 + 8 = 16 \]

4. **Nitrogen Dioxide (NO₂)**:
- Nitrogen has 7 electrons, and each oxygen has 8 electrons (2 oxygen atoms).
- Total electrons in NO₂:
\[ 7 + (2 \times 8) = 7 + 16 = 23 \]

### Step 4: Compare the Total Electrons
- CO has 14 electrons.
- NH₃ has 10 electrons.
- N₂ has 14 electrons.
- O₂ has 16 electrons.
- NO₂ has 23 electrons.

### Step 5: Identify the Isoelectronic Species
From the calculations:
- CO (14 electrons) is isoelectronic with N₂ (14 electrons).

### Conclusion
CO is isoelectronic with N₂.

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