Before you submit an error, please consult our Video Help page. Science Trek is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, ...

Get unlimited access to ad-free articles and exclusive content. Standard atomic weights, those numbers emblazoned under the elements on the periodic table, were once thought of as unchanging constants ...

In 2002, a team of Russian and American scientists created the first ever atom of oganesson, which is the heaviest chemical element ever recorded to date. With an atomic number of 118, oganesson ...

AN important result of the development of Moseley's atomic number rule has been the impetus it has given to the search for missing elements. It is true that later arrangements of the Periodic Table ...

As of 2019, the Periodic Table of the Elements has been around for 150 years. Maybe you've felt a certain chemistry with 2019 but don't know why? Maybe it's because this year marks the 150th ...