Giant Covalent Structures

Part of the Structure and Bonding section of Coddy's Chemistry journey. Lesson 36 of 49.

In silicon dioxide, SiO₂ (quartz, sand), each Si is bonded to four O and each O to two Si, through the whole crystal. SiO₂ is a ratio, not a molecule.

A giant covalent structure: melting means breaking covalent bonds, so the melting point is very high (quartz about 1700 °C). Hard, insoluble, no conduction.

Each Si-O bond is polar covalent: oxygen is far more electronegative than silicon.

Challenge

Quartz, the mineral of sand and glass, is silicon dioxide: every silicon atom is bonded to four oxygen atoms. Describe one Si-O bond: what kind of bond it is, and which atom carries the negative end.

Try it yourself

Bond typeDescribe the bond Si–O

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Structure and Bonding

2Covalent Bonds

Sharing Electrons Counting Valence Electrons Drawing Lewis Structures Double and Triple Bonds Lone Pairs Formal Charge Lewis Structures of Ions Recap - Molecule Builder

5Forces Between Molecules

London Forces Dipole-Dipole Forces Hydrogen Bonds Boiling Points Like Dissolves Like Recap - Boiling Contest

8Practice Problems

Recap - Polar Bonds Survey Recap - Pigments and Hexane Recap - Butanol and Ether Recap - Dots on an Oxide

3Shapes of Molecules

Electron Groups Linear and Trigonal Planar Tetrahedral Molecules Pyramids and Bent Molecules Bond Angles Recap - Shape Detective

6Metals and Giant Structures

Metallic Bonding Diamond and GraphiteGiant Covalent StructuresFour Kinds of Substance Recap - Material Match