Question

why does silicon dioxide have a higher melting point than sodium chloride

Answer 1

It has a very high melting point as the ionic bond is very strong between them. More force is required to break down. Silicon dioxide is a giant covalent structure. It also has the highest melting point because the covalent bonds between them is the strongest.

Answer 2

Silicon dioxide has a higher melting point than sodium chloride.

• Silicon dioxide exists as a giant covalent structure where each Si atom is connected to four oxygen atoms and each oxygen atom is connected to two Si atoms.
• Thus very high energy is required to break the covalent bonds. So, it possesses a higher melting point.
• Again NaCl has an ionic bond between Na and Cl atoms. Thus low energy is required to break the bond and have a low melting point.