Diamond is

Options

A. an insulator
B. a conductor
C. a semiconductor
D. none of these

Answer

### Step-by-Step Solution:

1. **Understanding the Composition of Diamond**:
- Diamond is composed entirely of carbon atoms. Each carbon atom forms four strong covalent bonds with four other carbon atoms.

2. **Structure of Diamond**:
- The arrangement of carbon atoms in diamond forms a three-dimensional tetrahedral lattice. This structure is characterized by each carbon atom being sp³ hybridized, meaning that the electrons are tightly bound in covalent bonds.

3. **Hybridization**:
- In sp³ hybridization, one s orbital and three p orbitals of carbon mix to form four equivalent sp³ hybrid orbitals. Each of these orbitals overlaps with the orbitals of neighboring carbon atoms to form strong covalent bonds.

4. **Electron Availability**:
- In the diamond structure, all four valence electrons of each carbon atom are involved in bonding with neighboring carbon atoms. This results in no free electrons being available for conduction.

5. **Conductivity of Diamond**:
- Since there are no free electrons to move and carry charge, diamond does not conduct electricity. Therefore, it behaves as an electrical insulator.

6. **Conclusion**:
- Based on the above points, we conclude that diamond is an insulator.

### Final Answer:
Diamond is an insulator.

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