Photosynthesis

5. any member of the most important class of pigments involved in photosynthesis
6. light generated from a natural light source
8. basic particle of the chemical elements
9. the weather of a big region
11. a colorless, odorless flammable gas that is the main constituent of natural gas. It is the simplest member of the alkane series of hydrocarbons.
13. an article or substance that is manufactured or refined for sale.
16. the smallest unit that lives on its own in the human body
17. membrane-bound cell organelles
18. is made by one or more atoms
19. the amount of water vapor in the air

1. the action of setting something on fire or starting to burn.
2. a chemical process in which a substance reacts rapidly with oxygen and gives off heat.
3. transition from one thing to another
4. is a type of organism
5. water which collects as droplets on a cold surface when humid air is in contact with it.
7. we breathe this
10. is a way for plants to convert carbon dioxide to oxygen
12. water in gaseous instead of liquid form
14. a substance that takes part in and changes a reaction.
15. is a compound that has been purified or prepared, especially artificially.