Giant molecular structures are best described as:

Giant molecular structures are best described as:

• A. A 3D network of covalent bonds throughout the structure
• B. A lattice of ions arranged in a repeating array
• C. A metallic lattice with delocalized electrons
• D. A collection of discrete molecules bound by weak forces

Answer: (A)

Giant molecular structures are held together by covalent bonds that extend throughout the entire solid, forming a continuous 3D network. This means there aren’t separate, individual molecules stuck together by weak forces; instead every atom is covalently bonded to many neighbors in all directions. That network of strong bonds gives these substances very high melting points and great hardness, as breaking the structure requires breaking many strong covalent bonds at once. Examples include diamond and quartz, where the whole material behaves like one huge molecule. The other descriptions don’t fit as well. An ionic lattice is built from repeating positive and negative ions held by electrostatic attraction, not a network of covalent bonds. A metallic lattice involves a lattice of positive ions with a sea of delocalized electrons—different bonding and bonding pattern than a covalent network. A collection of discrete molecules bound by weak forces describes molecular solids, where there are individual molecules held together by van der Waals forces or hydrogen bonds—there is no continuous covalent network throughout the solid.

Giant molecular structures are held together by covalent bonds that extend throughout the entire solid, forming a continuous 3D network. This means there aren’t separate, individual molecules stuck together by weak forces; instead every atom is covalently bonded to many neighbors in all directions. That network of strong bonds gives these substances very high melting points and great hardness, as breaking the structure requires breaking many strong covalent bonds at once. Examples include diamond and quartz, where the whole material behaves like one huge molecule.

The other descriptions don’t fit as well. An ionic lattice is built from repeating positive and negative ions held by electrostatic attraction, not a network of covalent bonds. A metallic lattice involves a lattice of positive ions with a sea of delocalized electrons—different bonding and bonding pattern than a covalent network. A collection of discrete molecules bound by weak forces describes molecular solids, where there are individual molecules held together by van der Waals forces or hydrogen bonds—there is no continuous covalent network throughout the solid.