The “lead” of a pencil is actually made of a substance called graphite which is made of carbon atoms. The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and ...

This year marks the 150th anniversary of the publication of Mendeleev’s Periodic Table of Chemical Elements in 1869. In celebration, the United Nations Educational, Scientific, and Cultural ...

The periodic table is part of the bedrock of chemistry education. Students use it to look up values like an element’s atomic mass, and it serves as a visual reference for the trends in physical ...

In the 1860s, the chemists, Lothar Meyer and Dmitri Mendeleev, independently presented the first periodic system. Since then, the well-known tabular arrangement of the elements has been the guiding ...

The periodic table is one of the triumphs of science. Even before certain elements had been discovered, this chart could successfully predict their masses, densities, how they would link up with other ...

Every student deserves to be able to independently explore periodic trends in a chemistry course; with the Accessible Audio Periodic Table, students can now access a free tool that incorporates ...

All matter–oceans, land, atmosphere, humans, animals, plants, food, materials, products, buildings–is made from 118 known chemical elements. These elements are ordered in the periodic table of ...