`CaC_(2)` molecule has

Options

A. one `sigma` bond and one `pi` bond between the two carbon atoms
B. one `sigma` bond and two `pi` bonds between the two carbon atoms
C. one `sigma` bond and one and a half `pi` bonds between the two carbon atoms
D. one `sigma` bond between the two carbon atoms

Explanation

To determine the number of sigma (σ) and pi (π) bonds in the calcium carbide (CaC₂) molecule, we can follow these steps:

### Step 1: Identify the structure of CaC₂
Calcium carbide is composed of calcium ions (Ca²⁺) and carbide ions (C₂²⁻). The C₂²⁻ ion consists of two carbon atoms.

### Step 2: Determine the bonding in the C₂²⁻ ion
The C₂²⁻ ion has a triple bond between the two carbon atoms. A triple bond consists of one sigma bond and two pi bonds.

### Step 3: Count the bonds in the C₂²⁻ ion
- **Sigma Bonds (σ)**: 1 (from the triple bond)
- **Pi Bonds (π)**: 2 (from the triple bond)

### Step 4: Consider the bonding in the entire CaC₂ molecule
In the CaC₂ molecule, the calcium ion (Ca²⁺) is ionic and does not contribute to sigma or pi bonds. The bonding we are interested in is solely from the C₂²⁻ ion.

### Step 5: Conclusion
Thus, in the calcium carbide (CaC₂) molecule, there is:
- **1 sigma bond**
- **2 pi bonds**

### Final Answer:
The CaC₂ molecule has 1 sigma bond and 2 pi bonds.

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