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Nonmetallic elements

 Column 1 (IA) metals are the only elements with a single s‐electron in their highest quantum levels. Elements in column 1 (IA) achieve the stable configuration of the next lowest quantum level when they lose their single s‐electron from the highest principal quantum level. For example, if sodium (Na) with the electron configuration (1s2, 2s2, 2p6, 3s1) loses its single 3s electron (Na+1), its electron configuration becomes that of the stable noble element neon (1s2, 2s2, 2p6) with the “stable octet” in the highest principle quantum level. Similar behavior is true for Li+1, K+1, and the other univalent (+1) cations in column 1 (IA).

 Column 2 (IIA) metals are the only elements with only two electrons in their highest quantum levels in their electrically neutral states. Column 2 (IIA) elements achieve stability by the removal of two s‐electrons from the outer electron shell to become divalent (+2) cations.

 Columns 3–12 (IIIB through IIB) transition elements are situated in the middle of the periodic table. Column 3 (IIIB) elements tend to occur as trivalent (+3) cations by giving up three of their electrons (s2, d1) to achieve a stable electron configuration. The other groups of transition elements, from column 4 (IVB) through column 12 (IIB) are cations that occur in a variety of ionization states. Depending on the chemical reaction in which they are involved, these elements can give up as few as one s‐electron as in Cu+1, Ag+1, and Au+1 or as many as six or seven electrons, two s‐electrons, and four or five d‐electrons as in Cr+6, W+6, and Mn+7. An excellent example of the variable ionization of a transition metal is iron (Fe). In environments where oxygen is relatively scarce, iron commonly gives up two electrons to become Fe+2 or ferrous iron. In other environments, especially those where oxygen is abundant, iron gives up three electrons to become smaller Fe+3 or ferric iron.