Scientific discovery

2. the release of a gas
5. a way of describing a material with particular physical characteristics
6. the gas we breathe out is carbon ...
10. plants... water through their roots and sunlight through their leaves
11. the kind of industry which produces medicines
13. a natural or chemical material used by farmers to help grow crops
14. chemicals used to kill unwanted insects
15. a chemical found in diamonds and coal
18. an increase of gases in the athmosphere leading to global warming - ... effect
19. an abbreviation for gases which have now been removed from aerosol to protect the ozone layer

1. a nuclear accident may cause ... of the surrounding area
3. the chemicals derived from petrol or natural gas
4. the chemicals added to food are called food ...
7. the different types of synthetic material which can be moulded and shaped to make many products
8. the opposite of synthetic
9. Mixing chemicals may cause a chemical ...
12. a form of energy from nuclear power which is dangerous to humans and animals
16. a household chemical product used to disinfect
17. another word for poisonous