Can you name everything from Ac to Zr? Test your knowledge of the periodic table and see if you can top the leaderboard ...

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 ...

The periodic table on the website of the International Union of Pure and Applied Chemistry avoids making a decision about whether La and Ac or Lu and Lr are group 3 elements.

Periods and families in the periodic table are described. Organization of the Periodic Table: Periods and families in the periodic table are described. Students learn to determine the number of ...