What are the roles of core and valance electrons in determing chemistry of an element?
The valence electrons are the ones that are used in chemical bonding. Metals tend to give away electrons, forming + ions,. Nonmetals tend to take electrons, forming – ions. Nonmetals also can share electrons. Each atom is trying to get 8 electrons in the valence shell. Metals giving away the outer ones, nonmetals taking electrons to fill the outer shell,, or sharing to fill it. The core electrons do little, but with the transition elements (center of the periodic table) there can be more than one oxidation number due to the just inner level participating also.
