Which of the following pairs of ions are isoelectronic and isostructural?

Options

A. `CO_(3)^(2-),NO_(3)^(-)`
B. `ClO_(3)^(-),CO_(3)^(2-)`
C. `SO_(3)^(2-),NO_(3)^(-)`
D. `ClO_(3)^(-),SO_(3)^(2-)`

Explanation

To determine which pairs of ions are isoelectronic and isostructural, we need to analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Isoelectronic and Isostructural:**
- **Isoelectronic:** Ions or molecules that have the same number of electrons.
- **Isostructural:** Ions or molecules that have the same structure or geometry.

2. **Analyzing Each Option:**
- **Option 1: CO3²⁻ and NO3⁻**
- **CO3²⁻:**
- Carbon (C) has 6 electrons, and each Oxygen (O) has 8 electrons.
- Total electrons = 6 (C) + 3 * 8 (O) + 2 (for the charge) = 32 electrons.
- Structure: Trigonal planar.
- **NO3⁻:**
- Nitrogen (N) has 7 electrons, and each Oxygen (O) has 8 electrons.
- Total electrons = 7 (N) + 3 * 8 (O) + 1 (for the charge) = 32 electrons.
- Structure: Trigonal planar.
- **Conclusion:** Both are isoelectronic and isostructural.

- **Option 2: ClO3⁻ and CO3²⁻**
- **ClO3⁻:**
- Chlorine (Cl) has 17 electrons, and each Oxygen (O) has 8 electrons.
- Total electrons = 17 (Cl) + 3 * 8 (O) + 1 (for the charge) = 32 electrons.
- Structure: Trigonal pyramidal.
- **Conclusion:** Different structures. Not isostructural.

- **Option 3: SO3²⁻ and NO3⁻**
- **SO3²⁻:**
- Sulfur (S) has 16 electrons, and each Oxygen (O) has 8 electrons.
- Total electrons = 16 (S) + 3 * 8 (O) + 2 (for the charge) = 42 electrons.
- **NO3⁻:** Already calculated above with 32 electrons.
- **Conclusion:** Different number of electrons. Not isoelectronic.

- **Option 4: ClO3⁻ and SO4²⁻**
- **SO4²⁻:**
- Sulfur (S) has 16 electrons, and each Oxygen (O) has 8 electrons.
- Total electrons = 16 (S) + 4 * 8 (O) + 2 (for the charge) = 50 electrons.
- **Conclusion:** Different number of electrons. Not isoelectronic.

3. **Final Conclusion:**
- The only pair that is both isoelectronic and isostructural is **Option 1: CO3²⁻ and NO3⁻**.

### Answer:
The correct answer is **Option 1: CO3²⁻ and NO3⁻**.