The periodic table of elements (often known simply as the periodic table) has been helping scientists with their work for a little over 150 years. The handy visual reference guide organizes known ...

The Periodic Table is an amazing chemistry tool that is organized with elements in order of increasing atomic number. The properties of the element change as you move across the row, but are similar ...

The ions formed have a full outer electron shell, so are very stable. See the study guide on groups in the periodic table for more information.

National Periodic Table Day, observed annually on February 7, honors one of the most significant achievements in scientific ...