Bonding

• what is a compound?

  atom of different element bonded together
• what are ions?


  singles atoms which have loosed/gained an electron to get a full outer shell
• what is ionic bonding? 


  electrostatic attraction holds positive and negative ions together
• what is sulfates symbol?


  SO₄²-
• what is hydroxides symbol?


  OH¯
• what is nitrates symbol?

  NO3-
• what is carbonates symbol?

  CO₃²⁻
• what is ammoniums symbol?


  NH₄⁺
• what are ionic crystals?

  giant lattices of ions
• ionic structure:

  • conduct electricity when molten/dissolved - ions free to move but in solid they are in a fixed position by strong ionic bonds
  • high melting points - giant ionic lattices are held by strong electrostatic forces and needs a lot of energy to overcome
  • dissolve in water - water molecules are polar. some parts have negative/positive charges. charges pull ions away from lattice, causing it to dissolve
• what is covalent bonding?

  shared pair of electrons to achieve a full outer shell
• what is a macromolecular structure?

  giant covalent structure have a huge network of covalently bonded atoms
• how is graphite slippery?

  • weak bonds between layers are easily broken, so sheets slide over each other
  • used in dry lubricant pencils
• how is graphite an electrical conductor?

  delocalised electrons are free to move around, not attached to carbon atoms
• how does graphite have low density?

  • layers are far apart compared to lengths of covalent bonds
  • used in lightweight equipment's
• graphite has very high melting points - strong covalent bonds in the hexagon sheets
• graphite is insoluble in any solvent
• what is diamond made of?

  each carbon atom is covalently bonded to four other carbon atoms - arrangements in a tetrahedral shape
• due to diamonds strong covalent bonds:

  • it has a very high melting point
  • extremely hard (drills and saws)
  • vibrations travel easily through stiff lattice - good thermal conductor
  • cant conduct electricity - outer electrons are held in localised bonds
  • wont dissolve in any solvent
  • can cut diamond to form gemstones - structure make it refract light, so it sparkles
• what is a charge cloud?

  an area where an electron pair is. the electrons don't stay still - they whizz around in the cloud
• electrons are negatively charged, so charge cloud repel each other, that's why in an atom electrons sit far away from each other
• shape of charge cloud affects how much it repels other charge clouds
• lone-pair charge clouds repel more then bonding-pairs
• greatest angels are between lone pairs of electrons
• bond angles between bonding pairs are reduced since they are pushed together by lone-pair repulsion
• lone pair/lone pair angles are the biggest
• lone pair/bonding pair angles are second biggest
• bonding-pair/bonding pair angles are the smallest
• what is linear's bond angle?

  180 degrees
• how many lone pairs does linear have?

  0
• how many electron pairs does linear have?

  2
• what is trigonal planar's bond angle?

  120 degrees
• how many electron pairs does trigonal planar have?

  3
• how many lone pairs does trigonal planar have?

  0
• what does linear shape look like?

  
• what does trigonal planar look like?

  A) what is the bond angle?

  
• what is tetrahedral's bond angle?

  109.5 degrees
• how many electron pairs does tetrahedral have?

  4
• how many lone pairs does tetrahedral have?

  0
• what does tetrahedral look like?