 Cliff Notes I. Groups A. group: a vertical column in the periodic table B. elements in the same groups have similar properties C. Group 1 - alkali metals Group 2 - alkaline earth metals Group 3-12 - transition metals Group 17 - halogens Group 18 - noble gases II. Characteristics of Groups A. alkali metals - metals, highly reactive, never found in elemental form in nature, low electronegativity (gives away one electron) B. alkaline earth metals - metals, highly reactive (but less than alkali metals), never found in elemental form in nature, low electronegativity (gives away 2 electrons) C. transition metals - metals, include radioactive elements, have various chemical properties D. halogens - non-metals, occur in combined form in nature (e.g. F2, Cl2, Br2), highly electronegative (gains one electron) E. noble gases - non-metals, all gases, non-reactive, have a full outer-energy level |