This document is a periodic table of elements that lists the atomic number, name, atomic weight, and symbol of each element. It arranges the 118 known elements in increasing atomic number and groups elements with similar properties, with metals on the left, nonmetals on the right, and noble gases and actinoids below the main body of the table. Elements that do not have stable isotopes are given with the mass number of the longest-lived isotope in parentheses.