The number of six membered carbon rings in the structure of Buckminsterfullerene (i.e. `C_60`)is .

Explanation

To determine the number of six-membered carbon rings in the structure of Buckminsterfullerene (C₆₀), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of C₆₀**:
- Buckminsterfullerene, or C₆₀, is a molecule composed of 60 carbon atoms arranged in a spherical shape resembling a soccer ball.

2. **Identify the Types of Rings**:
- In the structure of C₆₀, there are two types of carbon rings: six-membered rings (hexagons) and five-membered rings (pentagons).

3. **Count the Rings**:
- It is known from the structural analysis of C₆₀ that there are a total of 20 six-membered rings and 12 five-membered rings.

4. **Conclusion**:
- Therefore, the number of six-membered carbon rings in the structure of Buckminsterfullerene (C₆₀) is **20**.

### Final Answer:
The number of six-membered carbon rings in the structure of Buckminsterfullerene (C₆₀) is **20**.