Checked content

File:Periodic table discovery periods.png


English: Periodic Table, main "discovery periods"
Date 2004
Author IUPAC


  • Before 1800 (38 elements): discoveries during and before the age of enlightenment.
  • 1800-1849 (+22 elements): science and industrial revolutions.
  • 1850-1899 (+23 elements): the age of classifying elements recived the impulse of the spectrum analysis. Boisbaudran, Bunsen, Crookes, Kirchhoff, and others "hunting wikipedia:emission line signatures".
  • 1900-1949 (+13 elements): impulse with the wikipedia:old quantum theory and wikipedia:quantum mechanics.
  • 1950-present (+22 elements): "post atomic bomb" issues for atomic numbers 97 and above (colliders, bombardment techniques).


© The copyright holder of this file allows anyone to use it for any purpose, provided that the copyright holder is properly attributed. Redistribution, derivative work, commercial use, and all other use is permitted.

The following pages on Schools Wikipedia link to this image (list may be incomplete):


Learn more about Schools Wikipedia

Schools Wikipedia was created by children's charity SOS Children's Villages. The world's largest orphan charity, SOS Children's Villages brings a better life to more than 2 million people in 133 countries around the globe. We have helped children in Africa for many years - you can help too...