One might ask what is periodicity? The word periodicity has many meanings. Periodicity is defined as the occurrence of similar properties in elements having similar positions in the periodic table. Periodicity is found through certain periodic trends. There are four periodic trends found in the periodic table: atomic radius, ionization energy, electron affinity, and electronegativity. The first periodic trend is atomic radius. Atomic radius is found in several ways. The radii of some atoms are …showed first 75 words of 601 total…

…showed last 75 words of 601 total…element. Electronegativity values generally decrease going down a group, and they increase going across a period. The noble gases do not form very many chemical compounds, and they are not normally included in electronegativity. These four periodic trends have helped to arrange the elements, and the helped to give the periodic table its unique shape. It is a shame, Dmitri Mendeleev never got to see what a masterpiece he really created over a decade ago.