BUY IT HERE: Periodic table of sewing elements poster
Some discussion remains ongoing regarding the placement and categorisation of specific elements, the future extension and limits of the table, and whether there is an optimal form of the table. In the standard periodic table, the elements are listed in order of increasing atomic number Z. A new row is started when a new electron shell has its first electron. Columns are determined by the electron configuration of the atom; elements with the same number of electrons in a particular subshell fall into the same columns oxygen and selenium are in the same column because they both have four electrons in the outermost p-subshell.