Cliff Notes I. Review A. Draw atoms using shell models B. When filling up shells, last shell usually isn't full II. Valence Electrons A. valence electrons: the e- on the outermost shell of an atom -Examples: Nitrogen has 5 valence e- Number of valence e- in Sulfur? Calcium? B. Electron Dot Diagram: used to show number of valence electrons in periodic table 1. draw dots in one at a time on each side -Examples: draw electron dot diagrams of Nitrogen, Sulfur, Calcium C. Elements in the same group have the same number of valence e- D. Octet rule: elements are stable when their valence shell is full (8 e-) |