Bonding

• Covalent bonding


  Non-metal atoms can share electrons with other non-metal atoms to obtain a full outer shell of electrons
• Covalent bond formation


  1. Two atoms share pairs of electrons

  2. They form covalent bonds
• Molecules


  When two or more atoms are covalently bonded together
• Covalently bonded substances


  • May consist of small molecules or giant molecules
• Intermolecular forces


  Weak forces that exist between individual molecules
• Methane molecule


  • Four hydrogen atoms covalently bonded to a carbon atom
  • Weak intermolecular forces between individual methane molecules
• Bonding electrons


  Shared electrons that occur in pairs
• Non-bonding electrons


  Electrons on the outer shell which are not involved in the covalent bond(s)
• Simple covalent molecules do not conduct electricity as they do not contain free electrons
• A key difference between covalent bonds and ionic bonds is that in covalent bonds the electrons are shared between the atoms, they are not transferred (donated or gained) and no ions are formed
• Simple covalent molecules


  • Tend to have small molecular structures, such as Cl2, H2O or CO2