The diamagnetic species is

Options

A. NO
B. `NO_2`
C. `O_2`
D. `CO_2`

Explanation

To determine which species is diamagnetic, we need to analyze the electronic configurations of the given species. A diamagnetic species is one that has all its electrons paired, resulting in no net magnetic moment. Here’s a step-by-step solution:

### Step 1: Identify the species and their electron counts
We need to consider the electron configurations of the given species. The question does not specify which species to analyze, so we will assume common examples such as O2, NO, NO2, and CO2 based on the transcript.

### Step 2: Count the total number of electrons for each species
1. **O2 (Oxygen)**: Each oxygen atom has 8 electrons, so O2 has 16 electrons (8 + 8).
2. **NO (Nitric Oxide)**: Nitrogen has 7 electrons and oxygen has 8 electrons, so NO has 15 electrons (7 + 8).
3. **NO2 (Nitrogen Dioxide)**: Nitrogen has 7 electrons and each oxygen has 8 electrons, giving NO2 a total of 23 electrons (7 + 8 + 8).
4. **CO2 (Carbon Dioxide)**: Carbon has 6 electrons and each oxygen has 8 electrons, resulting in CO2 having 22 electrons (6 + 8 + 8).

### Step 3: Analyze the electron pairing
- **O2**: Despite having an even number of electrons (16), it has unpaired electrons in its molecular orbital configuration, making it paramagnetic.
- **NO**: With 15 electrons, it has unpaired electrons, making it paramagnetic.
- **NO2**: With 23 electrons, it also has unpaired electrons, making it paramagnetic.
- **CO2**: With 22 electrons, all electrons are paired, making it diamagnetic.

### Step 4: Conclusion
From the analysis, CO2 is the only species that is diamagnetic because it has all its electrons paired.

### Final Answer
The diamagnetic species is **CO2**.

---