Electronic Configurations of Atoms Valence electrons are electrons on the outermost shell of the atom. TABLE 1-1 Electronic Configurations of the Elements of the First and Second Rows Element Configuration Valence Electrons H l 1 He 1s2 2 Li 1s22J 1 Be 1s222 2 B 1s22s22p 3 C 1s2222p2py 4 N 1s2222p2p2p 5 0 1s22s22p22p2p 6 1s22s22p22p32p Ne 1s22s22p22p2p 8 Copyright 2010 Pearson Prentice Hall,Inc. Chapter 1 6Chapter 1 6 Electronic Configurations of Atoms • Valence electrons are electrons on the outermost shell of the atom