Template:Periodic table legend/Age of discovery

Background color shows age of discovery:
Antiquity to Middle Ages	Middle Ages–​1799	1800–​1849	1850–​1899	1900–​1949	1950–​1999	Since 2000
(12 elements) Antiquity to Middle Ages: unrecorded discoveries up into the Middle Ages	(22 elements) Discoveries during the age of enlightenment	(25 elements) Scientific and industrial revolutions	(24 elements) The age of classifying elements; application of spectrum analysis techniques: Boisbaudran, Bunsen, Crookes, Kirchhoff, and others "hunting emission line signatures"	(14 elements) Development of old quantum theory and quantum mechanics	(16 elements) Post Manhattan project; synthesis of atomic numbers 98 and above (colliders, bombardment techniques)	(5 elements) Recent synthesis