bonding and structure (c2)

• Ions

  Charged particles
• Gaining/losing electrons


  • Requires energy
• Ionic bonding


  1. Metals react with non-metals

  2. Electrons in outer shell of metal atom are transferred

  3. Metals lose electrons and become positively charged (cations)

  4. Non-metals gain electrons and become negatively charged (anions)
• Ionic compounds

  • Giant structure of ions
  • Held together by strong electrostatic forces of attraction between oppositely charged ions
  • Forces act in all directions
  • High melting and boiling point
  • Strong bonds
  • Conduct electricity when molten or dissolved in water
• Ball and stick limitations

  
  

  not to scale

  no information about strength of attraction, movement of electrons,
• Covalent bonding

  Sharing of electron pairs between two non-metals
• Covalent compounds

  • Small molecules
  • Strong bonds
  • Weak intermolecular forces (between atoms)
  • Same covalent bonding structures are very large (molecules, polymers, strong intermolecular forces)
• Dot and cross diagramslimitations

  • doesn't show 3D arrangement of atoms
  • doesn't show size of atoms
• Giant covalent structures

  • Solid
  • Strong
  • High melting point
  • Most don't conduct electricity
• Metallic bonding


  Bonding between metals
• Metallic compounds

  • Giant structure of atoms arranged in regular pattern
  • Electrons in the outer shell are delocalised
  • Conduct electricity and thermal energy
  • Sharing of delocalised electrons gives rise to strong metallic bonds
  • Electrostatic attraction holds everything together
  • Strong
  • High melting and boiling point
  • Malleable
• Alloys

  • Two or more different elements (metals)
  • Combination of different size atoms
  • Disrupts regular structure so layers can no longer slide
  • Much harder than pure metals
• Simple molecular substances

  • Relatively low melting and boiling points
  • Weak intermolecular forces between molecules
  • Intermolecular forces increase with size of molecules
  • Do not conduct electricity
• States of matter

  • Solid: strong forces of attraction, held together in fixed position, definite shape and volume
  • Liquid: weak forces of attraction, free to move, definite volume but no definite shape
  • Gas: very weak forces of attraction, free to move, no definite shape or volume
• Nanoparticles


  • Extremely tiny particles 1-100 nm
  • Large surface area to volume ratio
  • Smaller quantities needed to be effective
  • Uses: catalysts, drug delivery, electronics, cosmetics
  • Issues: very new, unknown effects on body and environment, could damage cells
• 2d model limitation


  only show arrangement for one layer of ions
• covalent bonds features

  • small moeluses
  • strong
  • weak intermollecular forces
• diamond

  • stong
  • bonded to 4 other carbon atoms
  • high boiling point
  • doesnt conduct electricity
• graphene

  • single layer of graphite
  • strong
  • conduct electricity
• graphite

  • bonded to 3 other carbon atoms
  • flat sheets of hexagons
  • no bonds between layers
  • soft
  • high melting point
  • conduct electricty
• fullerenes

  • carbon atoms that form hollow shapes
  • first buckminster (c60)
  • large SA:V ratio
  • nanotubes have high length to diamter ratio
• uses of fullerenes/nanotubes

  • industrial catalysts
  • deliver drugs
  • strengthen materials