When Mendeleev first published the original periodic table in 1869, it contained only 63 elements — about half as many as there are today. His table had gaps to leave room for elements that had ...

When Mendeleev first published the original periodic table in 1869, it contained only 63 elements — about half as many as there are today. His table had gaps to leave room for elements that had ...

The iconic periodic table of elements, devised in rudimentary form by the Russian chemist Dmitri Mendeleev, has since evolved into a two-dimensional array of the chemical elements ordered by ...

Mendeleev was the creator of the original Periodic Table of the Elements, which he literally dreamed up one night in 1869, after falling asleep at his desk with 65 note cards arrayed in front of ...

Mendeleev left blank spaces in his original periodic table so that he could properly line up the known elements. Gallium, element 31, was his first gap to be filled, in 1875. The star of a popular ...

But how many of these elements do you know? Test your knowledge and compete with other Live Science readers to see who can ...