Covalent Bonding

• Covalent Bonds

  Strong force that joins atoms - weakest bond of the 3

  • Non-metal + non-metal
  • Sharing electrons
  • Need full outer shells
  • Molecules = 2 or more atoms joined by covalent bonds
  • No need to draw the inner circles
• Covalent: Bond Types

  • Show by using dot & cross diagram or solid line
  • Bond type = # of "-" stacked
  • eg:
  • double: = single: -
• Simple Covalent Structures

  • Molecular solids = covalent bonds that are solids
  • eg: iodine
  • Held together by weak forces of attraction
  • No -ve or +ve attraction
• Properties of Mollecular Solids

  • Low melting & boiling points
  • Soft & brittle (usually)
  • Usually insoluble in water
  • Soluble in other solvents
  • Can't conduct electricity (exception: carbon)
• Properties of Graphite

  • Giant structure that grows in flat planes (horizontal)
  • Has layers
  • Soft & slippery
  • Layers can easily glide over each other (weak attraction)
  • Can be used as lubricant
  • Can conduct electricity - free electron from every atom to carry a charge