Periodic Table Basics

What Is the Periodic Table?

The periodic table is a big chart that shows all the chemical elements.
Each box holds an element’s name, symbol, and a tiny number called the atomic number.

How Elements Are Organized

Elements are placed in rows called periods and columns called groups.
Elements in the same group behave in similar ways.
The table starts with hydrogen on the left and ends with the heavy, rare elements on the right.

Fun Facts

• The table has 118 known elements.
• The lightest element, hydrogen, is a gas; the heaviest, oganesson, is a metal.
• Scientists use the table to predict how new substances will act.