Periodic table

The periodic table is structured with elements arranged by increasing atomic numbers across rows, known as periods, and similar properties in vertical columns, called groups. This layout, largely unchanged since Dmitri Mendeleev's development in 1869, has been adapted over time.

How are the elements organized in the periodic table?

What is the significance of the vertical columns in the periodic table?

How has the layout of the periodic table changed over the years?

What has remained largely unchanged in the periodic table since its development?

Who developed the periodic table and in what year?