The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.

What is the periodic table and how does it work?

The periodic table is a graphical collection of element data. The table lists the chemical elements in order of increasing atomic number, which is the number of protons in an atom of an element. The rows (periods) and columns (groups) organize elements according to similar properties.

How is the periodic table arranged?

In the modern periodic table, the elements are listed in order of increasing atomic number. ... In a periodic table arranged in order of increasing atomic number, elements having similar chemical properties naturally line up in the same column (group).