What's Happening in Erie County. 1  September 1 - September 30 : Agricultural Districts Open Enrollment Period. 2  September 4 : Erie County Government offices are closed today. 3  September 5 : Justice Assistance Grant (JAG) Public Notification - Fiscal Year 2017.
Definition. 1  As a noun, the common definition of chemical is a substance that is produced or used in a process (reaction) involving changes to atoms or molecules. 2  As an adjective, chemical means of or pertaining to chemistry.
chemistry. the science that treats of the elements and atomic relations of matter, and of the various compounds of the elements. colloid chemistry. chemistry dealing with the nature and composition of colloids. inorganic chemistry. the branch of chemistry dealing with inorganic compounds.