Silicon Dioxide Silica Structure Revealed

The video explains the structure of silica, focusing on SiO4 units where each silicon atom is tetrahedrally bonded to four oxygen atoms. The structure forms a three-dimensional network through covalent bonds, creating cyclic rings of alternating silicon and oxygen atoms. The molecular formula of silica is SiO2, not SiO4, because each oxygen atom is shared between two silicon atoms, resulting in a 1:2 silicon to oxygen ratio.

What is the bond angle formed by the silicon atom in the SiO4 unit?

• 120°

• 109°

• 90°

• 180°

How are the oxygen atoms in the SiO4 unit bonded to silicon atoms?

• Covalent bonds

• Ionic bonds

• Hydrogen bonds

• Metallic bonds

What type of structure is formed by the repetition of tetrahedral units in silica?

• Amorphous structure

• Cyclic ring structure

• Planar structure

• Linear structure

Why is the molecular formula of silica SiO2 instead of SiO4?

• Each silicon atom is bonded to only two oxygen atoms.

• Each oxygen atom is shared by two silicon atoms.

• Each oxygen atom is shared by four silicon atoms.

• Each silicon atom shares all four oxygen atoms completely.

What is the ratio of silicon to oxygen in the silica structure?

• 1:1

• 1:4

• 1:3

• 1:2