How does the Periodic Table work?
The layout of the periodic table demonstrates recurring (“periodic”) chemical properties. Elements are listed in order of increasing atomic number (i.e. the number of protons in the atomic nucleus). Rows are arranged so that elements with similar properties fall into the same vertical columns (“groups”). According to quantum mechanical theories of electron configuration within atoms, each horizontal row (“period”) in the table corresponded to the filling of a quantum shell of electrons. There are progressively longer periods further down the table, grouping the elements into s-, p-, d- and f-blocks to reflect their electron configuration. In printed tables, each element is usually listed with its element symbol and atomic number; many versions of the table also list the element’s atomic mass and other information, such as its abbreviated electron configuration, electronegativity and most common valence numbers. Hope this helps.
