This is a standard display of the periodic table of the elements. For more information on its contents and history, see the article Periodic table. Notes Lanthanides are also known as "rare earth elements", a deprecated term. Regarding group membership of these elements, see here. Alkali metals, alkaline earth metals, transition metals, actinides, lanthanides, and poor metals are all collectively known as "metals". Halogens and noble gases are also non-metals.