The number of sigma `(sigma)` and pi `(pi)` bonds present in acetylene are _____ respectively.

Options

A. Three sigma bonds and two pi bond
B. Three sigma bonds and one pi bond
C. One sigma bond and two pi bonds
D. Three pi bonds and three sigma bonds

Explanation

To determine the number of sigma (σ) and pi (π) bonds present in acetylene (C₂H₂), we can follow these steps:

### Step 1: Understand the Structure of Acetylene
Acetylene has the molecular formula C₂H₂. It consists of two carbon atoms and two hydrogen atoms. The structure can be represented as:

```
H - C ≡ C - H
```

### Step 2: Identify the Types of Bonds
In acetylene, the two carbon atoms are connected by a triple bond, and each carbon atom is also bonded to a hydrogen atom.

### Step 3: Count the Sigma Bonds
- A **single bond** consists of **1 sigma bond**.
- A **double bond** consists of **1 sigma bond + 1 pi bond**.
- A **triple bond** consists of **1 sigma bond + 2 pi bonds**.

In acetylene:
- The triple bond between the two carbon atoms contributes **1 sigma bond**.
- Each carbon atom forms a **single bond** with a hydrogen atom, contributing **2 sigma bonds** (one from each C-H bond).

Thus, the total number of sigma bonds is:
- **1 (from C≡C) + 2 (from C-H bonds) = 3 sigma bonds**.

### Step 4: Count the Pi Bonds
From the triple bond between the two carbon atoms:
- The triple bond contributes **2 pi bonds**.

### Step 5: Summarize the Results
In acetylene, we have:
- **3 sigma bonds**
- **2 pi bonds**

Therefore, the number of sigma and pi bonds present in acetylene are **3 and 2**, respectively.

### Final Answer
The number of sigma (σ) and pi (π) bonds present in acetylene are **3 and 2**, respectively.

---