Question

An example of a network solid is:

• A. $\text{SiO}_2$
• B. $\text{MgO}$
• C. $\text{CaF}_2$
• D. $\text{ZnS}$

Hint:

Network solids are characterized by: 1. High melting points due to strong covalent bonds. 2. Insolubility in most solvents. 3. Examples: Diamond ($\text{C}$), $\text{SiO}_2$, Boron Nitride ($\text{BN}$).

Answer 1

The Correct Option is A

A network solid is a chemical compound in which atoms are bonded covalently in a continuous network extending throughout the material. Key examples include: $\text{SiO}_2$ (Silicon dioxide): Forms a 3D covalent network where each Si atom is tetrahedrally bonded to four O atoms, and each O atom bridges two Si atoms. $\text{MgO}$ (Magnesium oxide): Ionic solid, not covalent network. $\text{CaF}_2$ (Calcium fluoride): Ionic crystal. $\text{ZnS}$ (Zinc sulfide): Exists as either ionic or molecular solid depending on form, but not a classic network solid like $\text{SiO}_2$. Thus, the correct answer is (1).

Answer 2

Step 1: Understand what a network solid is.
Network solids are substances where atoms are bonded by covalent bonds in a continuous network extending throughout the material.
They have high melting points, hardness, and do not consist of discrete molecules.

Step 2: Identify examples of network solids.
Common examples include diamond (carbon), silicon carbide (SiC), and silicon dioxide (\(\text{SiO}_2\)).
These compounds have a 3D network structure formed by strong covalent bonds.

Step 3: Conclusion.
Therefore, an example of a network solid is \(\text{SiO}_2\).