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Who developed the first widely recognized periodic table of chemical elements?

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Periodic table of the elements with color-coded categories and labeled element groups, showing atomic numbers, symbols, and basic information for each chemical element. — periodic table Modern version of the periodic table of the elements. To learn an element's name, atomic number, electron configuration, atomic weight, and more, select one from the table.

The Russian chemist Dmitri Mendeleev is credited with developing the first widely recognized periodic table of chemical elements in 1869.1

While other scientists, such as Alexandre-Émile Béguyer de Chancourtois and John Newlands, had previously attempted to classify elements by atomic weight, Mendeleev’s work was distinguished by his focus on both atomic weight and valence. Crucially, Mendeleev left gaps in his table for elements that had not yet been discovered, accurately predicting the existence and properties of elements such as scandium, gallium, and germanium.12

Although Mendeleev’s initial table was based on atomic weight, it laid the foundation for the modern periodic law. It was not until the early 20th century that scientists determined an element's position is actually defined by its atomic number, or the number of protons in its nucleus.21