c2

• Covalent Bonding

  Non-metallic elements, sharing electrons, forms molecules

  
• Ionic bonding

  Metals, giving/gaining electrons, forms ions

  
• Metallic bonding

  Atoms are the same size, regular formation, highest energy electron shell are delocalised. Electrostatic forces between the electrons and the positive ions hold the structure together.

  
• Giant ionic structures

  Strong electrostatic forces, high m.p/b.p

  
• Simple molecules

  Low m.p/b.p, no overall charge so unable to conduct, weak intermolecular forces

  
• Giant covalent structures/Macromolecules

  High m.p/b.p, lattice, lots of covalent bonds
• Diamond


  Each carbon atom forms 4 bonds, hard, transparent, giant covalent structure

  
• Graphite

  Each carbon atom forms 3 bonds, form layers of graphite, soft, giant covalent structure, conduct electricity due to delocalised electrons between layers

  
• Fullerenes

  Hexagonal rings of carbon atoms, join together to form a structure, some atoms are nano-sized, used for drug delivery, suncream, lube

  
• Alloys

  Metal layers slide, alloys are mixtures of metals, distort the layers
• Shape-memory alloys

  Bent or deformed into different shapes, when heated return to original shape, used in glasses and dental braces
• Conducting in metals

  Delocalised electrons, quickly transfer energy to positive ions, vibrate more
• Polymer properties

  Depend on the monomers, low density and high density depend on reaction conditions (temp., catalyst)
• Thermosoftening polymers

  Tangled, soft when heated, hardens as it cools so can be remoulded, weak intermolecular forces

  
• Thermosetting polymers

  Don't melt or soften when heated, strong covalent bonds, cross links between chains hold polymer chains

  
• Nanoscience

  Extremely tiny, behave differently to the normal atoms, large surface areas, suncream and deodorant, research needed
• Paper chromotography

  Solvent, pencil line, substances move different distances depending on their solubility, analyse food colours/additives

  
• Gas Chromotography

  Mixture carried as a gas through a column packed with particles of a solid, individual compounds travel through the column at different times, times are recorded and make their retention times
• Mass Spectrometry

  Linked to the gas chromatography, peaks in charts show the relative molecular masses of compounds (molecular ion peak)
• Collision theory - surface area

  More collisions in the same time,
• Collision theory - temperature

  Frequency of collisions increases, particles have more energy so collisions are more likely to result in a reaction as they reach the activation energy
• Collision theory - concentration/pressure

  Increase in particles, increase in collision frequency
• Catalyst


  Quickens rate of reaction without being used up, metals/enzymes are used in industry, research into nanoparticles
• Exothermic

  Releases heat, combustion, oxidation, neutralisation, used in hand warmers
• Endothermic


  Takes in heat, need to be heated continuously to keep the reaction going, used in instant cold packs
• Bases


  React with acids and neutralise them
• Acid + Base (or alkali)


  Salt + Water
• Acid + Metal


  Salt + Hydrogen
• Insoluble Salts

  Mix solutions of soluble salts containing the ions needed
• Electrolysis

  Passing electricity through a compound when it is molten or in solution to break it down, solution broken down is the electrolyte
• Positive electrode (anode)

  Negative ions lose electrons, oxidation, some form molecules
• Negative electrode (cathode)

  Positive ions gain electrons, reduction
• Extraction of aluminium

  Electrolysis, mixed with molten cryolite to lower melting point, aluminium at negative, oxygen at positive, electrodes made of carbon so oxygen reacts forming carbon dioxide, electrodes replaced regularly
• Electrolysis of brine

  Sodium chloride, forms chlorine gas (positive electrode), hydrogen gas (negative electrode), sodium hydroxide solution.
• Electroplating


  Electrolysis, object plated is at negative electrode, electrolyte contains metal ions