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 section in the middle of the table is called the Transition Metals. If you know what one of the elements in a group is like, you can make predictions about the other elements in a group.

Scientists have found that our bodies need 28 different elements to function properly. These are almost one-quarter of the periodic table and are mainly found in the first four periods.