Quick learn

• Distillation


  Simple - separate liquid from solution based on boiling point, lowest boiling evaporates first, collect vapour then cool down, used to get pure water from salt water

  Fractional - lowest boiling point first, evaporate and collected the vapour, cool down
• History of the atom

  John Dalton - solid sphere in the 19th century

  JJ Thomson - plum pudding model, 1897

  Ernest Rutherford - alpha particle scattering experiment, nuclear model, 1909

  Bohr - electron shells

  Rutherford - protons, neutrons
• Electronic structure


  2 electrons, 8 electrons, 8 electrons
• Development of the periodic table

  Early 1800s - physical and chemical properties, relative atomic mass, not complete, placed in the wrong group

  Dmitri Mendeleev, 1869 - order of atomic mass, gaps for future elements with similar properties
• Modern atomic table

  • 100 elements roughly
  • Increasing atomic (proton) number
  • Metals are on the left, Non-metals on the right
  • Columns - similar properties, called groups, group number indicated the amount of electrons in the outer shell (Group 0 is the expection)
• Group 1 - Alkali Metals


  Down: reactivity increases, lower melting/ boiling point, higher relative atomic mass as you go down
• Group 7 - Halogens


  Down: less reactive, higher melting/ boiling point, higher relative atomic mass
• Group 0 - Nobel Gases


  Down: boiling point increases due to the number of electrons rising
• Formation of ions

  • Electrons are transferred
  • Charged particles
  • Atoms always want a full outer shell
  • If electrons lost, positive ion
  • If electrons gained, negative ion
• Ionic bonding

  • Between metals and non-metals
  • Metals loses an electrons (positive ions), non-metals gains an electrons (negative ions)
  • Strongly attracted to each other via electronic forces
• Ionic compounds

  • Closely packed
  • Oppositely charged particles
  • High melting/ boiling points due to strong bonds
  • Easily dissolved in water
  • Carry electrical charge
• Covalent bonding

  • Non-metals bonding with each other
  • They share electrons
  • Electrostatic forces
  • Only share outer shell
• Polymers and Giant covalent structures

  Polymers - lots of small units form a long molecule (repeating section), strong covalent bonds, lower boiling points

  Giant covalent structures - all atoms are bonded, high melting/ boiling points, no electric charge, main examples: diamond, graphite, silicon dioxide
• Allotropes of carbon


  Diamond - 4 covalent bonds, really hard, high melting point, no electrical charge

  Graphite - 3 covalent bonds, hexagons, induvial layers, high melting points, conduct electricity due to delocalised electron

  Graphene - 1 layer of graphite
• Metallic bonding

  • Bonding between metals
  • Electrostatic attraction, positive ions and negative electrons
  • Very strong
  • Delocalised electrons
  • High melting points
• Relative formula mass

  Mr - all relative atomic mass of a compound added together

  Ar - relative atomic mass (top number)
• The mole


  Number of atoms or molecules of any substance
• Limiting reactants 


  Reaction stops when one reactant is used up
• Reactions of acids


  acid + metal oxide -> salt + water

  acid + metal hydroxide -> salt + water

  acid + metal carbonate -> salt +water + carbon dioxide
• Reactivity series

  A) Potassium

  B) Sodium

  C) Lithium

  D) Calcium

  E) Magnesium

  F) Aluminium

  G) Zinc

  H) Iron

  I) Copper

  J) Silver

  K) Gold

  
• Separating metals from metal oxide

  Some metals can be extracted with carbon, if the ore is less reactive then carbon.
• Redox reaction

  • Loss of electrons is called oxidation
  • Gain of electrons is called reduction
  • REDuction and OXidation happen at the same time, hence REDOX
• Bond energies

  Exothermic - bond formed, energy released

  Endothermic - bond broken, energy lost