Covalent bonding

• What is a covalent bond?


  A shared pair of electrons between atoms.
• When are covalent bonds formed?


  When a non-metal reacts with a non-metal.
• What do 2 shared electrons make?


  A single bond.
• What do 4 shared electrons make?

  A double bond
• What do 6 shared electrons make?


  A triple bond
• What is different about elements in period 3 and below (covalent bonds.)


  They can fit more than 8 electrons in their outer shell (Because of d orbitals)
• When does a dative covalent bond form?


  When the shared pair of electrons in the covalent bond come from only one of the bonding atoms.
• What are examples of elements with dative covalent bonds?


  • NH$4^+$
  • SO$4^{2-}$
  • BCL3
  • SF6
  • ALCL$4^-$
• How do you show a dative covalent bond on a diagram?


  An arrow which points from the atom that is providing the lone pair to the atom that is electron deficient.
• What are examples of covalently bonded molecules?


  • PF3 and PF5
  • PCL3 and PCL5
  • PH3 and PH5
  • NH3
  • H2S
  • SO2
  • CO2
• How does the length of the bond affect the strength of a covalent bond?


  The shorter the bond, the stronger the bond (usually).
• How are double bonds different to single bonds?


  They are stronger