1. Properties
   1. CnH2n
   2. change gradually through group
   3. Subtopic 2
   4. unsaturated
      1. one or more double carbon bond
      2. C=C
      3. makes them reactive
   5. burn well
   6. reactive in other ways
      1. add bromine water
         1. alkenes
            1. decolourise solution
         2. alkAnes
            1. not reactive
         3. distinguishes alkenes / alkanes
         4. ethene
         5. colourless gas
         6. bromine
         7. brown liquid
         8. 1,2-dibromoethane
         9. colourless liquid
         10. ADDITION REACTION
   7. combustion
      1. O2
         1. CO2 + H2O
         2. Low O2
            1. CO
            2. incomplete combustion
   8. uses
      1. make polymers
         1. ADDITION reactions
         2. polythene
   9. shape
      1. equilateral triangle
2. Group
3. Formation
   1. Cracking Process
4. Addition Reactions
   1. bromine
   2. hydrogen
      1. catalyst needed
      2. makes alkane
      3. ethene + hydrogen ---> ethane
      4. make margarine
         1. vegetable oil
            1. unsaturated C=C
            2. add H
            3. saturated
            4. harder