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.
A chemical element or element is a chemical substance consisting of atoms having the same number of protons in their atomic nuclei (i.e. the same atomic number, Z).he properties of the chemical elements are often summarized using the periodic table, which powerfully and elegantly organizes the elements by increasing atomic number into rows (periods) in which the columns (groups) share recurring (periodic) physical and chemical properties.