A systematic arrangement of the chemical elements.
A systematic arrangement of the chemical elements. The periodic table is organised so that the elements' atomic numbers increase consecutively along the rows, or periods, and elements in the same vertical column, or group, tend to have similar properties. The layout has been adapted over the years, but the basic form of the periodic table has remained largely unchanged since its development by Dmitri Mendeleev in 1869.
The periodic table is organised so that the elements' atomic numbers increase consecutively along the rows, or periods, and elements in the same vertical column, or group, tend to have similar properties. The layout has been adapted over the years, but the basic form of the periodic table has remained largely unchanged since its development by Dmitri Mendeleev in 1869.