Diamond, silica and silicon carbide are:

Options

A. lonic solid
B. Covalent solid
C. Metallic solid
D. Molecular solid

Explanation

To determine the type of solids that diamond, silica, and silicon carbide represent, we can analyze their structures and bonding characteristics step by step.

### Step 1: Analyze Diamond Structure
- **Description**: Diamond is composed of carbon atoms that are arranged in a tetrahedral structure. Each carbon atom forms four covalent bonds with four other carbon atoms, resulting in a three-dimensional (3D) network.
- **Conclusion**: This arrangement leads to a very strong and rigid structure, characteristic of a covalent network solid.

### Step 2: Analyze Silica Structure
- **Description**: Silica (SiO₂) consists of silicon and oxygen atoms. Silicon, which is in the same group as carbon, can also form four bonds. In silica, each silicon atom is bonded to four oxygen atoms in a tetrahedral arrangement, creating a continuous network.
- **Conclusion**: Like diamond, silica forms a covalent network solid due to the strong covalent bonds between silicon and oxygen atoms.

### Step 3: Analyze Silicon Carbide Structure
- **Description**: Silicon carbide (SiC) has a structure similar to that of diamond. Silicon atoms are tetrahedrally coordinated with carbon atoms. Each silicon atom bonds with four carbon atoms, and each carbon atom bonds with four silicon atoms, forming a continuous 3D network.
- **Conclusion**: This structure also qualifies as a covalent network solid due to the presence of strong covalent bonds throughout the material.

### Final Conclusion
- **Type of Solids**: All three materials—diamond, silica, and silicon carbide—are classified as **covalent network solids** due to their strong covalent bonding and 3D network structures.

### Answer
The correct answer is that diamond, silica, and silicon carbide are **covalent solids** or **covalent network solids**.

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