What primarily gives giant covalent structures their high melting/boiling points?

• A. Strong covalent bonds
• B. Ionic bonds
• C. Hydrogen bonds
• D. Weak van der Waals forces

Answer: (A)

Giant covalent structures have a network of strong covalent bonds extending throughout the whole solid. Because every atom is bonded to several neighbours in a 3D lattice, melting or boiling means breaking a vast number of these strong bonds. The energy required to sever so many covalent bonds is enormous, which gives these materials extremely high melting and boiling points. Other types of bonding—ionic bonds, hydrogen bonds, or van der Waals forces—are not the primary bonds holding the entire network together in these substances, so they don’t account for such high temperatures. In short, the extensive, very strong covalent bonding throughout the structure sets the high temperatures.