Pollutants and Alternative fuels

123456789101112
Across
  1. 4. from complete combustion of fuels
  2. 6. type of fog, made up of harmful chemicals
  3. 10. causes irritation to the respiratory system
  4. 11. formed in the high temperatures of a car engine
Down
  1. 1. general formula CxHx
  2. 2. produces a large amount of nirtogen oxide emissions
  3. 3. what is an issue with sulfur oxides
  4. 5. has 12 carbons in its chain
  5. 7. from the incomplete combustion of fuels
  6. 8. engines can be easily converted to run on this fuel
  7. 9. only product of its combustion is water
  8. 12. produces less carbon monoxide, sulfur dioxide and nitrogen oxides than petrol