Today, the periodic table is organized by atomic number, which is the number of protons in the nucleus. But they didn’t know about protons then, so they organized everything by atomic weight.

150 years ago, Russian chemist Dmitrii Mendeleev created the periodic table of the elements, revolutionizing chemistry. Skip to content. Subscribe or renew today ...

Elements 113, 115, 117 and 118 to be added to the periodic table. The seventh row of the table will now be complete. Scientists to devise permanent names for new elements ...

2019 is the International Year of the Periodic Table. The person who typically gets credit for its creation is Dimitri Mendeleev. But there were many more chemists who should be recognized.

Mendeleev also did something special with the gaps on the table. All the early periodic tables had holes where no known element fit. We know today they simply hadn't been discovered yet.

A new study lays the groundwork to expand the periodic table with a search for element 120, to be made by slamming electrically charged titanium atoms, or ions, into a californium target.

The periodic table lists 118 different chemical elements. And yet, for thousands of years, humans have really, really liked one of them in particular: gold. A chemist explains.