realizing that it reflected the number of protons in an atom's nucleus. What had, until then, been a rather arbitrary numbering system was given a specific meaning - and in 1914, Moseley realized that ...

Proving a hypothesis can be exciting, but witnessing something that has never been seen before elevates that discovery into ...

As such, they were able to confirm that, like its neighbours, promethium’s atom experiences a phenomenon known as “lanthanide contraction”, which packs the electrons in more tightly to the ...