Covalent bonding

• How are covalent bonds formed?

  It is when two non-metal atoms share a pair of electrons between two atoms so each has a full shell.
• What are some common molecular elements?

  Carbon, hydrogen, oxygen, nitrogen.
• What are the names of common molecular compounds?

  Water, Carbon dioxide, Ammonia, Methane.
• What is the structure of covalent bonds?

  -small groups of atoms/simple molecular structure.

  -very strong covalent bonds.

  -forces of attraction are weak.

  -no charge.
• What are the properties of covalent bonds?

  -low melting/boiling points due to feeble intermolecular forces which are easy to break.

  -don't conduct electricity.

  -few are soluble in water.
• Explain the formation of covalent bonds using dot and cross diagrams.


  Since covalent bonds share electrons an example could be O2.

  An oxygen atom needs two more electrons to be complete so they share electrons to both be full.
• What is the approximate size of atoms and small molecules?

  1 x 10-10m.
• Why are covalent compounds poor conductors of electricity?

  They lack free-moving charged particles.
• Describe the structure of a polymer.


  A chain of monomers.
• What are monomers?

  Monomers are small molecules that can join together to form larger molecules called polymers.
• Why do polymers have higher melting/boiling points than monomers?

  Longer polymers have more intermolecular forces.
• Give some examples of monomers and their polymers.

  Butene = Polybutene.

  Propene = Polypropene.

  Pentene = Polypentene.

  Hexene = Polyhexene.
• Give an example of a molecular compounds.

  Water. There are two hydrogen atoms and one oxygen atom.