The periodic table of elements is a method of displaying the chemical elements in a table. It was first devised in 1869 by the Russian chemist Dmitri Mendeleev. He intended the table to illustrate periodic trends in the properties of the elements. The layout od the table has been perfected and extended over time because new elements are being discovered and new theoretical models have been developed to explain chemical behavior. Various different layouts are possible, however, the most common forms are still quite similar to Mendeleev's original. …
