Which of the following lists all the giant covalent structures named in the material?

• A. Diamond, Graphite, Silicon Dioxide
• B. Diamond, Graphite
• C. Silicon Dioxide
• D. Diamond, Silicon Dioxide

Answer: (A)

Giant covalent structures are solids formed by a continuous network of covalent bonds throughout the material, not individual molecules. In the material you're studying, the giant covalent structures named are diamond, graphite, and silicon dioxide. Diamond and graphite are both forms of carbon, with diamond having a rigid three-dimensional network of strong covalent bonds, making it extremely hard and with a very high melting point. Graphite has layers of carbon atoms bonded strongly in two dimensions, but weaker bonds between layers, which gives it some different properties like lubrication and conductivity along the layers. Silicon dioxide is a network solid where silicon and oxygen form a vast, extended lattice of covalent bonds, also with a very high melting point and no discrete molecules.

Therefore, the list that includes all three—diamond, graphite, and silicon dioxide—is the complete set of giant covalent structures named in the material. The other options miss one of these structures, so they aren’t the full list.