Periodic table Periodic table The periodic table, or periodic table of elements, is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties, whose structure shows "periodic trends". Generally, within one row (period) the elements are metals to the left, and non-metals to the right, with the elements having similar chemical behaviours placed in the same column. Table rows are commonly called periods and columns are called groups. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also
Alternative periodic tables each element has with respect to another element in the table. Other tables aim to emphasize the chemical element isolations by humans over time. Charles Janet's Left step periodic table (1928) is considered to be the most significant alternative to the traditional depiction of the periodic system. It organizes elements according to orbital filling (instead of valence) and is widely used by physicists. Compared to the common layout, the Left step table has these changes: A modern version of the periodic table is constructed by Valery Tsimmerman, named the ADOMAH periodic table (2006). Its structure is based on the four