c4

c4

1. testing water purity

   • test 4 sulfate
     • add hydrocloric acid
       • add barium chloride solution
         • if whie precipitate there is
   • test 4 halide ions
     • add dilute nitric acid
       • add 10 drops of silver nitrat solution
         • if precipitate fors yes there is

2. elements

   • isotopes
     • different form of the same element
     • same number of protons
     • different number of nutrons
     • same atomic number different mass number
     • eg carbon 12 and carbon 14
       • carbon 12
         • 6 protons
         • 6 electrons
         • 6 nutrons
       • carbon 14
         • 6 protons
         • 6 electrons
         • 8 neutrons
     • the number of nutrons is mass - atomic number
   • group number of electrons in outer shell

3. metals

   • crystal structure
     • same properties
     • special bonding that is in metals
     • held together with metalic bonding
     • outer electron moves freely
     • this creates a sea of free electrons
   • high
     • very hard dense and shiney
     • strong atraction between
       • positive ions
       • delocalised electrons
     • high melting and boling point
       • large energy needed to break the metallic bonds
     • strenght of the metallic bond decreases as atomic radious increases
       • and melting point
   • strong
     • hard to break
       • high tensil streangth
     • hammered into different shapes
       • malleable
   • good conducters
     • the delocolised electrons carry the electrical curent
     • they also carry heat energy
   • use
     • sausepan
       • stainless steal
         • good heat conducter
     • electric wiring
       • copper
     • aeroplane
       • aluminium
     • bridge
       • steel

4. ion and ionic componds

   • ions
     • charged particals
   • ou have to balance the + and -
     • 2K+
       • k20
         • the potassium ion 1+ and the oxygen 2- balance because you need 2 positive to the 2 negetive
     • O2-
   • dot and cross diagram
     • show what happens in ionic bonding
     • arrows to

5. electron shells

   • shells
     • 2nd = 8
     • 3rd =8
     • 1st =2
   • electronic configeration
     • eg. 12= 2,8,2

6. superconducters

   • at low teperatures
     • all have some resistance
     • mean some eletrical energy turns to heat
     • if cold enough
       • it disdsapears
     • dont loose any current
   • the catch
     • you can make
       • powet cables with no lose
       • fast electronic circuites
       • strong electromagnets
     • has to be colder than -265 c
       • hard and expencive
   • transition metals
     • catalysts
       • iron
         • harbor process
       • nickel
         • hydrogenation
     • colorful
       • copper often blue
       • iron (ll) often light green
       • iron (lll) often orange or brown
     • middle of the table
       • have typical metallic propities

7. atoms

   • the nucleus
     • positive protons
     • netrule neutrons
     • the nucleus it positive
   • electrons
     • negitivly charged
     • the electronic shell
     • virtually no mass
   • atomic number and mass
     • mass top number
     • mass total of protons and nutron
     • atomic number
       • number of protons
       • bottom number
       • number of electrons

8. ionic bonding

   • transfering electrons
     • atom loses or gains an electron
     • forms a charged partical
       • ions
     • strongley atracted to each other
       • +
         • join together
       • -
   • one electron on a shell got to go
     • they like to hace a full outer shell
     • once they get rid thy become positivley charged
     • they will leapat the chance to stick to a negativ ion
   • nearly full shell wants an extra
     • gain an electron to fill the shell
     • become negetivly charged
   • eg
     • sodium gives up an electron
       • NA+
     • chlorine picks p an atom
       • CL-
         • forms ionic bond
   • giant ionic lattice
     • made from metals and non metals
     • strong chemical bonds in all ions

9. groups

   • group 1 alkali metals
     • oxidation
       • loss of electrons
       • the more reactive the happier to lose
     • cold water
       • produces hydrogen gas
       • eg sodium
       • they fizz
       • reactivity increases the lower down the group
         • potasium get hot enough to ignight
         • sodium and potasium melt
       • alkali forms
         • 2 Na + 2 H2O > 2 NaOH + H2
     • burn with charicteristic colors
       • lithium =red
       • sodium =yellow
       • potassium = lilac
     • key facts
       • they all have one outer electron
       • low melting point
       • low density
       • very soft
       • they always form ionic
         • NEVER COVALENT
   • group 7 halogens
     • key facts
       • they all have 7 outer electrons
       • as you go down they become less reactive
         • melting point increase
       • at room tempreature
         • chlorine
           • poisonoius
           • dense green gas
           • fairley reactive
         • iodine
           • dark gray crystlline solid
         • bromine
           • poisonous
           • orange liquid
     • reduction
       • keenn to gain an electron
         • become a 1- ion
         • stabel electronic structure
       • the more reactive the happier it i to gain
       • gain of electrons is called reduction
     • form salts
       • react with alkli metals
         • makes salt called METAL HALIDES
       • reactions eg
         • 2 Na + Cl2 > 2 NaCl
           • Sodium + Chlorine > sodium chloride
         • 2 K + Br2 > 2 KBr
           • potassium + bromine > potassium bromide
     • displace
       • more reactive halogen dispalce less reactive ones
         • eg
           • Chlorine + potassium iodide > iodine+ potassium chloride

10. covalent bonding

    • sharing electrons
      • non metals combine to for convalent bonds
      • both atoms have a full outer shell
      • each provides one extra electron
    • dot and cross
      • overlap
    • simple molecular substances
      • covalent bods usely have simple molucal structures
        • eg H2O and CO2
      • held together with very strong covalent bonds
      • force between them is very weak
        • low boiling point
        • lowmelting point
      • at room tempreture gases and liquids
      • the dont conduct electricity
        • no free electrons

11. water purity

    • sea water
      • very expersive
      • in dry contrey r=they distill sea water
      • needs alot of energy
    • limited resorcesd
      • industrial coolent
      • homes for washing
      • ground water
        • aquifers
          • rocks trsp water
        • upto 70% of water comes from underground
      • ground water
        • eg lakes rivers reservoirs
          • run dry in summer
    • tap water
      • still contains in puritys
      • nitrate residue
        • fertalizer running off fields
      • lead compounds
        • from old pipes
      • pesicide residue
        • spraying to near lakes
    • tretment plants
      • filteration
        • wire mesh
        • takes out large twigs
      • sedimentation
        • iron sulphate is added
          • makes small particals clump together
      • chlorination
        • bubbled through to kill harmfull bacteria

12. thermal decomposition

    • hydroxide tests
      • copper (lll) = blue solid
      • iron (ll) = gray/green solid
      • iron (ll) = orange/brown solid
    • solid forms in solution
      • 2 solution react and make a solid in the solution
      • called a precipitate
    • breaking down with heat
      • breaks into at leat 2 other substances
      • break down into metal oxide and carbon dioxide
        • eg. copper oxide
      • check for carbon dioxide = lime water

13. history

    • theories backed up
      • so that it can be checked for errors
      • so other scientists can use it to develope there own work
    • time line
      • john darlton
        • jj thomson
          • rutherford
            • gold foil experimenthe came up with the thery of the nuclear atom found that the plum pudding was wrong
            • bohr
              • electrons can only exist in fixed orbits
                • it was pretty clos to our current accepted verrsion
          • found the charges and mass whch showed they wernt solid spheres new thery was called the plum pudding
        • described them as solid spheres and said that different spheres made different elements