Then
The table gave chemistry a unifying map and, when predicted elements such as gallium and germanium appeared, his scheme won over the field.
Timeline of Discovery · 21 / 30
Dmitri Mendeleev
1834 - 1907 · Russia
Dmitri Mendeleev arranged the elements into the periodic table — and boldly predicted the properties of elements no one had found yet.
- Chemistry
- Industrial & Modern
Lived
1834 - 1907
Era
Industrial & Modern
Primary field
Chemistry
Signature idea
Created the Periodic Table of Elements
Their place in history
1834 - 1907
The question they asked
Is there an order hidden inside the growing list of known chemical elements?
The Contribution
What this scientist actually did — precisely and plainly.
He organised elements by increasing atomic weight and arranged them so that similar properties recur periodically, leaving gaps that he predicted would be filled.
How the Work Advanced Knowledge
The tools, experiments and reasoning behind the discovery.
He studied element properties across the known repertoire, sorted by pattern, and used the table itself as a predictive tool rather than a catalogue.
Why It Mattered Then / Today
From their own moment in history to the world we live in now.
Today
The periodic table organises every chemistry classroom and laboratory, and the atomic (rather than weight) basis came later with Moseley, completing Mendeleev’s pattern.
Important Works or Discoveries
Landmarks that carried the idea into the world.
- The Periodic Law and the first periodic table
- Principles of Chemistry (textbook)
- Predicted properties of yet-unfound elements
I saw in a dream a table where all elements fell into place as required.
Sources
Where this profile was verified.
Last reviewed: 2026-09-22
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