Periodic trends

Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativity, ionization energy, electron affinity, atomic radii, ionic radius, metallic character, and chemical reactivity. Periodic trends arise from the changes in the atomic structure of the chemical elements within their respective periods (horizontal rows) and groups in the periodic table. These laws enable the chemical elements to be organized in the periodic table based on their atomic structures and properties. Due to the periodic trends, the unknown properties of any element can be partially known.Several exceptions, however, do exist, such as that of ionization energy in group 3, The electron affinity trend of group 17, the density trend of alkali metals aka group 1 elements and so on.