covalent bond and simple molecular structures

• What allows atoms to share electrons?

  Covalent bonding
• What is a covalent bond?

  Attraction between shared electrons and nuclei
• What does covalent bonding create?

  A stable molecule of bonded atoms
• What are examples of covalently bonded molecules?

  • Chlorine (Cl2)
  • Ammonia (NH3)
  • Water (H2O)
  • Methane (CH4)
• What do dot and cross diagrams represent?

  How non-metal atoms share electrons
• What determines the strength of a covalent bond?

  Energy needed to break the bond
• What is average bond enthalpy?

  Value measuring bond strength in kJ mol-1
• How does bond enthalpy relate to bond strength?

  Higher enthalpy indicates stronger covalent bond
• What is the bond energy of a N≡N triple bond?

  945 kJ mol-1
• What is the bond energy of a F-F single bond?

  159 kJ mol-1
• How many pairs of electrons can atoms share?

  Multiple pairs to form double or triple bonds
• How does oxygen form a double bond?

  By sharing 2 sets of electrons
• How does nitrogen form a triple bond?

  By sharing 3 sets of electrons
• What is dative covalent bonding?

  • Also called coordinate bonding
  • Both shared electrons come from one atom
• What are the requirements for dative covalent bonding?

  One atom must have a lone pair; other must be electron deficient
• How is a dative covalent bond represented?

  By an arrow showing electron donation
• How does ammonium NH4+ form a dative covalent bond?

  Nitrogen donates both shared electrons to H+
• What is the significance of lone pairs in dative covalent bonding?

  • Lone pairs can be donated
  • Essential for forming dative bonds