If the central atom is of third row or below this in the periodic table, then lone pair will occupy a stereochemically inactive s-orbital and bonding will be through almost pure p-orbitals and bond angles are nearly `90^(@)`, if the substituent's electronegativity value is `le 2.5`.
In which of the following option, covalent bond is having maximum s% character ?

Options

A. S-H bond in `H_(2)S`
B. P-H bond in `PH_(3)`
C. N-H bond in `NH_(3)`
D. All have equal s% character

Answer

To determine which covalent bond has the maximum s% character among the given options, we can follow these steps:

### Step 1: Understand the relationship between s% character and bond angles
The percentage of s character in a covalent bond is related to the bond angle. A higher bond angle indicates a greater s character. For example, a bond angle of 180° corresponds to 100% s character, while a bond angle of 90° corresponds to 0% s character.

### Step 2: Consider the electronegativity of the atoms involved
Electronegativity influences the bond character. The higher the electronegativity of an atom, the more s character the bond will have. This is because more electronegative atoms tend to pull electron density closer to themselves, which increases the s character.

### Step 3: Identify the electronegativity values of the relevant elements
- Nitrogen (N): Electronegativity ≈ 3.0
- Phosphorus (P): Electronegativity ≈ 2.1
- Sulfur (S): Electronegativity ≈ 2.5
- Oxygen (O): Electronegativity ≈ 3.5

### Step 4: Compare the electronegativities
From the electronegativity values:
- Nitrogen has the highest electronegativity (3.0).
- Oxygen follows (3.5), but it is not part of the options.
- Sulfur has a lower electronegativity (2.5).
- Phosphorus has the lowest electronegativity (2.1).

### Step 5: Determine the bond with the highest s character
Since nitrogen has the highest electronegativity, the bond involving nitrogen will have the maximum s character. The order of s character based on electronegativity is:
- N-N bond > P-P bond > S-S bond

### Conclusion
Thus, the covalent bond with the maximum s% character is the bond involving nitrogen.

### Final Answer
The correct option is the one that includes nitrogen.

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