The Periodic Table is organized with elements arranged in rows, or periods, according to increasing atomic number. Metals are located on the left of the periodic table, while nonmetals are located on the right. They are divided by a stairstep line. Elements touching the stairstep line are called metalloids because they have characteristics of both metals and nonmetals. The exception to the stairstep line is hydrogen. It is left of the stairstep line, but it is a nonmetal.
Families of elements are grouped in columns, with elements that have similar properties. Some of the notable families of elements include the noble gases (column 18), the halogens (column 17), the alkali metals (column 1) and the alkaline earth metals (column 2).
The transition metals are located in the center of the periodic table. They include many of the common metals, such as copper, iron, silver and gold. The two rows below the main body of the table are called the lanthanide and actinide series. They include the very heavy metallic elements, such as uranium and plutonium.
