Sum of `sigma and pi` bonds in `NH_(4)^(+)` cation is ..

Answer

To solve the question regarding the sum of sigma and pi bonds in the NH4+ cation, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of NH4+**:
- The ammonium ion (NH4+) consists of one nitrogen atom (N) and four hydrogen atoms (H).

2. **Draw the Lewis Structure**:
- In the Lewis structure of NH4+, nitrogen is the central atom, and it is bonded to four hydrogen atoms. Each hydrogen atom forms a bond with nitrogen.

3. **Identify the Types of Bonds**:
- Each bond between nitrogen and hydrogen is a single bond.
- A single bond is characterized as a sigma (σ) bond.

4. **Count the Sigma Bonds**:
- There are four N-H bonds in NH4+. Therefore, there are a total of 4 sigma bonds.

5. **Identify Pi Bonds**:
- There are no double or triple bonds in NH4+, which means there are no pi (π) bonds present.

6. **Calculate the Total**:
- The total number of sigma bonds is 4, and the number of pi bonds is 0.
- Therefore, the sum of sigma and pi bonds is:
\[ \text{Total} = \text{Number of Sigma Bonds} + \text{Number of Pi Bonds} = 4 + 0 = 4 \]

### Final Answer:
The sum of sigma and pi bonds in the NH4+ cation is **4**.