The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

As the diagram shows, this arrangement means that certain elements with similar properties ... Just four years before Mendeleev announced his periodic table, Newlands noticed that there were ...

The zigzag, staircase, line in the diagram of the periodic table above separates the metals, on the left, from non-metals, on the right. Hydrogen is a non-metal, but it is often put in the middle.

Browse a list of curated classroom activities by the American Association of Chemistry Teachers. Lesson Plans: The Periodic Table and Bonding Download inquiry-based lesson plans and activity sheets to ...