Of the following sets which one does not contain isoelectronic species?

Options

A. `BO_(3)^(3-) ,cO_(3)^(2-) ,NO_(3)^(-)`
B. `SO_(3)^(2-) ,CO_(3)^(2-) ,NO_(3)^(-)`
C. `CN^(-) ,N_2 ,C_(2)^(2-)`
D. `PO_(4) ^(3-) ,SO_(4)^(2-) ,CIO_(4)^(-)`

Explanation

To determine which set does not contain isoelectronic species, we need to calculate the total number of electrons for each species in the given sets. Isoelectronic species are those that have the same number of total electrons. Let's analyze each option step by step.

### Step 1: Calculate total electrons for each species in the first set (BO3, CO3, NO3)
1. **Boron (B)**: Atomic number = 5 (5 electrons)
2. **Oxygen (O)**: Atomic number = 8 (8 electrons)
- In BO3, there are 1 Boron and 3 Oxygens:
\[ \text{Total electrons in BO3} = 5 + (3 \times 8) = 5 + 24 = 29 \text{ electrons} \]

3. **Carbon (C)**: Atomic number = 6 (6 electrons)
- In CO3, there are 1 Carbon and 3 Oxygens:
\[ \text{Total electrons in CO3} = 6 + (3 \times 8) = 6 + 24 = 30 \text{ electrons} \]

4. **Nitrogen (N)**: Atomic number = 7 (7 electrons)
- In NO3, there are 1 Nitrogen and 3 Oxygens:
\[ \text{Total electrons in NO3} = 7 + (3 \times 8) = 7 + 24 = 31 \text{ electrons} \]

### Summary for the first set:
- BO3: 29 electrons
- CO3: 30 electrons
- NO3: 31 electrons

**Conclusion**: The first set does not contain isoelectronic species since the total number of electrons is different for each.

### Step 2: Calculate total electrons for the second set (SO3^2-, CO3^2-, NO3^-)
1. **Sulfur (S)**: Atomic number = 16 (16 electrons)
- In SO3^2-, there are 1 Sulfur and 3 Oxygens, plus 2 extra electrons due to the 2- charge:
\[ \text{Total electrons in SO3^2-} = 16 + (3 \times 8) + 2 = 16 + 24 + 2 = 42 \text{ electrons} \]

2. **Carbon (C)**: Atomic number = 6 (6 electrons)
- In CO3^2-, there are 1 Carbon and 3 Oxygens, plus 2 extra electrons due to the 2- charge:
\[ \text{Total electrons in CO3^2-} = 6 + (3 \times 8) + 2 = 6 + 24 + 2 = 32 \text{ electrons} \]

3. **Nitrogen (N)**: Atomic number = 7 (7 electrons)
- In NO3^-, there are 1 Nitrogen and 3 Oxygens, plus 1 extra electron due to the - charge:
\[ \text{Total electrons in NO3^-} = 7 + (3 \times 8) + 1 = 7 + 24 + 1 = 32 \text{ electrons} \]

### Summary for the second set:
- SO3^2-: 42 electrons
- CO3^2-: 32 electrons
- NO3^-: 32 electrons

**Conclusion**: The second set does not contain isoelectronic species since SO3^2- has a different total number of electrons compared to CO3^2- and NO3^-.

### Final Answer:
The set that does not contain isoelectronic species is the first set (BO3, CO3, NO3).