4.2 Covalent bonding

Covalent Bonding

• Formed by electrostatic attraction between a shared pair of electrons and the positive nuclei
• In ionic, atoms lose or gain electrons. In covalent, atoms share electrons to achieve noble gas configuration
• Occurs between non-metals
• There are single bonds (F₂), double bonds (O₂) and triple bonds (N₂)
• There is also HF for example in which H does not acquire a octet rule

Bond Strength and bond Length

• The trend in bond strength is:
  • Triple > double > single
• The trend in bond length is
  • Single > double > triple

Electronegativity

• Electronegativity is the relative attraction that an atom of an element has for the shared pair of electrons in covalent bond.
• It can be determined with electronegativity values the type of bond:
• To find Δen, subtract the electronegativity values for two atoms