High melting point of boron is due to its existence as

Options

A. Small covalent molecule
B. Giant covalent molecule
C. Giant covalent solid
D. Giant ionic molecule

Answer

To answer the question regarding the high melting point of boron, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Identify the Element**:
- Boron is the first element of Group 13 in the periodic table.

2. **Determine the Nature of Boron**:
- Boron is classified as a non-metal, which typically has different physical properties compared to metals.

3. **Understand the Structure of Boron**:
- Unlike many elements, boron does not exist in a simple atomic form. Instead, it forms a complex structure.

4. **Covalent Network Structure**:
- Boron exists in a lattice structure, specifically in a form known as an isoelectronic form. This means that boron atoms are arranged in a three-dimensional network.

5. **Strong Covalent Bonds**:
- In this lattice structure, boron atoms are held together by strong covalent bonds. These bonds require a significant amount of energy to break.

6. **Implications for Melting Point**:
- Because of the strong covalent bonds and the extensive network of atoms, boron has a high melting point. If boron existed as individual atoms, its melting point would be considerably lower.

7. **Conclusion**:
- Therefore, the high melting point of boron is due to its existence as a giant covalent structure, specifically in the form of a lattice.

### Final Answer:
The high melting point of boron is due to its existence as a **giant covalent structure** (option 3).

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