A large area of chemistry is polymer chemistry . Other fields include agrochemistry , astrochemistry ( and cosmochemistry ) , atmospheric chemistry , chemical engineering , chemical biology , chemo-informatics , electrochemistry , environmental chemistry , femtochemistry , flavor chemistry , flow chemistry , geochemistry , green chemistry , histochemistry , history of chemistry , hydrogenation chemistry , immunochemistry , marine chemistry , materials science , mathematical chemistry , mechanochemistry , medicinal chemistry , molecular biology , molecular mechanics , nanotechnology , natural product chemistry , oenology , organometallic chemistry , petrochemistry , pharmacology , photochemistry , physical organic chemistry , phytochemistry , polymer chemistry , radiochemistry , solid-state chemistry , sonochemistry , supramolecular chemistry , surface chemistry , synthetic chemistry , thermochemistry , and many others .