The sum of total number of lone - pairs of electrons and `sp^(3)` hybridized nitrogen atoms in Melamine is

Answer

To solve the problem, we need to determine the total number of lone pairs of electrons and the number of sp³ hybridized nitrogen atoms in melamine. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Structure of Melamine
Melamine has a specific molecular structure. It consists of three nitrogen atoms in a cyclic arrangement and additional nitrogen atoms attached to it.

### Step 2: Count the Lone Pairs of Electrons
1. Identify the nitrogen atoms in the structure of melamine.
2. Each nitrogen atom typically has one lone pair of electrons unless it is involved in a double bond.
3. In melamine, all nitrogen atoms have lone pairs.
4. Count the lone pairs:
- Each of the 3 nitrogen atoms in the cyclic structure has 1 lone pair.
- The nitrogen atoms attached to the NH₂ groups also have 1 lone pair each.
- Therefore, if there are 5 nitrogen atoms in total, each contributing 1 lone pair, we have:
- Total lone pairs = 5.

### Step 3: Identify the Hybridization of Nitrogen Atoms
1. Determine the hybridization of each nitrogen atom:
- The nitrogen atoms in the cyclic structure are connected by double bonds, indicating they are sp² hybridized.
- The nitrogen atoms attached to the NH₂ groups are sp³ hybridized because they have one lone pair and three bond pairs.
2. Count the sp³ hybridized nitrogen atoms:
- There are 3 nitrogen atoms that are sp³ hybridized (the ones in the NH₂ groups).

### Step 4: Calculate the Total
1. Now, sum the total number of lone pairs and the number of sp³ hybridized nitrogen atoms:
- Total lone pairs = 5
- Total sp³ hybridized nitrogen atoms = 3
- Total = 5 + 3 = 8.

### Final Answer
The sum of the total number of lone pairs of electrons and the sp³ hybridized nitrogen atoms in melamine is **8**.