The periodic table through time
Choose a year and watch today’s periodic table fill in. See which elements were available to chemists, which discoveries came after 1869, and where Mendeleev’s famous predictions were confirmed.
The grid keeps today’s element positions so changes are easy to compare. It is a historical timeline, not a facsimile of Mendeleev’s 1869 layout.
Before 1869
The periodic system did not appear from nowhere. Lavoisier, Döbereiner, de Chancourtois, Newlands and Lothar Meyer all contributed classifications or periodic relationships before Mendeleev’s publication.
1869 · Mendeleev
In this modern grid, 62 of today’s elements are present in 1869. Mendeleev’s historical table listed 63 entries because didymium was then treated as an element; it was later shown to be a mixture that yielded praseodymium and neodymium.