Question

Compare and contrast the structures of silica vs. silicates vs. glass.

a) Silica: network structure; Silicates: molecular structure; Glass: crystalline structure
b) Silica: amorphous structure; Silicates: network structure; Glass: molecular structure
c) Silica: molecular structure; Silicates: amorphous structure; Glass: network structure
d) Silica: crystalline structure; Silicates: amorphous structure; Glass: network structure

Answer 1

Silica typically exists as crystalline quartz or amorphous silica, silicates are minerals with a network structure that includes metals, and glass is an amorphous solid made from silica.

Step-by-step explanation:

To compare and contrast the structures of silica, silicates, and glass:

• Silica: typically found in crystalline form as quartz, which forms a regular, repeating three-dimensional structure known as a covalent network. Silicon dioxide (SiO₂), or silica, can also exist in an amorphous form, which does not have a long-range order.
• Silicates: these are minerals composed of silicon, oxygen, and one or more metals. They form a network structure similar to that of quartz, but the arrangement includes metals that influence the type of crystal structure formed.
• Glass: an amorphous solid made by cooling molten silica so rapidly that atoms do not have time to arrange into a crystal structure, resulting in a disordered, non-crystalline form.

Therefore, option (b) is the correct answer as it states silica has an "amorphous structure"; silicates have a "network structure"; and glass has a "molecular structure". However, the description for glass is not entirely accurate, as glass is actually an amorphous solid but is formed from a backbone of silica, similar to silicates, rather than having a molecular structure.