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