Bonding

• Monoatomic


  • Boiling/melting point are low
  • Heavier the atoms, the stronger the intermolecular forces
  • Gas at room temperature
• Conductivity


  Ability to conduct electricity
• Monoatomic


  • Do not conduct electricity
  • Insoluble in water
• Simple molecular


  • Boiling/melting points are low
  • Stronger the intermolecular forces, the higher the boiling/melting points
  • Do not conduct electricity
  • Insoluble in water
• Giant covalent


  • Very high melting point
  • High boiling point
  • Stronger the covalent bonds, the higher the melting/boiling points
  • Most cannot conduct electricity
  • Graphite can conduct due to delocalized electrons
• Boiling Melting points

  • High melting point
  • High boiling point
• Conductility


  Can conduct
• Aqueous solution and liquid

  Solubility (q) soluble in water
• Metallic


  • Boiling melting points- High melting point
  • High boiling point
  • Form move delocalised electrons, the stronger the bond
  • Conductivity- Good
  • Solubility (ag) - insoluble
• Dative bonding


  A lone pair on one element of donated to an ion
• Electronegativity


  The power of an atom to attract the electrons in a covalent bond
• Factors affecting electronegativity


  • Nuclear charge
  • Shielding
  • Atomic radius
• As you go across a period

  Nuclear charge increases, atomic radius decreases, electronegativity increases
• As you go up a group

  Shielding decreases, atomic radius decreases, electronegativity increases
• Polar bonds


  Occur when difference in electronegativity is between 0.6 and 2
• Van der Waals forces


  Attractive forces between molecules that are not covalently bonded
• Movement of electrons


  1. Shifts the electron cloud

  2. When electrons are on the same side, induces a temporary dipole

  3. Temporary dipole induces a dipole in the neighbouring atom
• The attraction between the induced dipole and the temporary dipole causes Van der Waals forces
• Van der Waals forces occur between atoms and molecules that are not covalently bonded
• Dipole-dipole forces


  Permanent charges on atoms attract each other
• Dipole-dipole forces


  • Atoms have permanent dipoles due to electronegativity differences
  • There are 3 polar bonds between the atoms
• Hydrogen bonds

  • Must have a lone pair
  • between hydrogen, nitrogen, fluorine or oxygen
• 2 bonding pairs

  • Linear
  • 180 bond angle
• 3 bonding pairs

  • Trigonal planar
  • 120 bond angle
• 4 bonding pairs

  • Tetrahedral
  • 109.5 bond angle
• 5 bonding pairs

  • Trigonal bipyramid
  • 1-120°
  • 2-90°
• 6 bonding pairs

  • Octahedral
  • 90 bond angle
• 2 bonding pairs 1 lone pair

  • Bent v-shape
  • 118 bond angle
• 3 bp 1 lp

  • prymidal
  • 107.5 degrees
• 2 bp 2 lp

  • V-shape
  • 105.5 degrees
• 4 bp 1 lp

  • See-saw
  • 118 and 88 degrees
• 3 bp 2 lp

  • T-shape
  • 88 degrees
• 5 bp 1 lp

  • Distorted square prymid
  • 88 degrees
• 4 bp 2 lp

  • Square planar
  • 90 degrees
• Diamond


  • Cannot conduct delocalized e-
  • Tetrahedral shape
• Graphite


  • Layers/sheet
  • Delocalized carry change through
  • Can conduct current
  • Can flow through
• Carbon


  • Strong bonds
  • Delocalized e-bonds
• Carbon


  • High melting boiling point due to strong bonds
  • Used in jewellery
• Graphite


  • Lubricant
  • Weak soft due to layers sliding
  • High lower melting boiling point
• Graphite is insoluble - not charged particles unlike ions