Among the following species, identify the isostuctural pairs
`NF_(3). NO_(3)^(-), BF_(3), H_(3)O, HN_(3)`

Options

A. `[NF_(3) ,NO_(3)^(Theta)]` and `[BF_(3) ,H_(3)O^(o+)]`
B. `[NF_(3) ,N_(3)H]` and `[NO_(3)^(Theta) , BF_(3)]`
C. `[NF_(3), H_(3)O^(o+)]` and `[NO_(3)^(Theta), BF_(3)]`
D. `[NF_(3) ,H_(3) O^(o+)]` and `[N_(3) H, BF_(3)]`

Explanation

To identify the isostructural pairs among the given species (NF₃, NO₃⁻, BF₃, H₃O, HN₃), we need to analyze the molecular geometry of each species. Here’s a step-by-step solution:

### Step 1: Determine the structure of NF₃
- **NF₃** has a nitrogen atom bonded to three fluorine atoms and has one lone pair on nitrogen.
- The molecular geometry is **trigonal pyramidal** due to the presence of the lone pair.

### Step 2: Determine the structure of NO₃⁻
- **NO₃⁻** (nitrate ion) has a nitrogen atom bonded to three oxygen atoms with one of the bonds being a double bond and the others being single bonds.
- The molecular geometry is **trigonal planar**.

### Step 3: Determine the structure of BF₃
- **BF₃** has a boron atom bonded to three fluorine atoms with no lone pairs.
- The molecular geometry is also **trigonal planar**.

### Step 4: Determine the structure of H₃O⁺
- **H₃O⁺** (hydronium ion) has a central oxygen atom bonded to three hydrogen atoms and has one lone pair.
- The molecular geometry is **trigonal pyramidal**.

### Step 5: Determine the structure of HN₃
- **HN₃** (hydrazoic acid) has a linear structure with nitrogen atoms connected in a straight line.
- The molecular geometry is **linear**.

### Step 6: Identify isostructural pairs
- From the analysis:
- **NF₃** and **H₃O⁺** are both **trigonal pyramidal**.
- **NO₃⁻** and **BF₃** are both **trigonal planar**.

Thus, the isostructural pairs are:
- **NF₃ and H₃O⁺**
- **NO₃⁻ and BF₃**

### Final Answer:
The isostructural pairs are:
- NF₃ and H₃O⁺
- NO₃⁻ and BF₃

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