Sulphur hexafluoride is used as a gaseous electrical insulator.

Explanation

### Step-by-Step Solution:

1. **Understanding the Structure of Sulfur Hexafluoride (SF6)**:
- Sulfur hexafluoride consists of one sulfur atom surrounded by six fluorine atoms.
- The molecular geometry of SF6 is octahedral, meaning the fluorine atoms are arranged symmetrically around the sulfur atom.

2. **Properties of SF6**:
- SF6 is a colorless, odorless gas at room temperature.
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