Strangely enough, the idea that black nitrogen didn’t exist has long been considered a mystery. The periodic table is arranged in recurring “periods” where each column is made up of elements ...

In the periodic table of elements there is one golden rule for carbon, oxygen, and other light elements. Under high pressures they have similar structures to heavier elements in the same group of ...

The elements on the periodic table of elements are listed in ways that emphasize certain relationships. There are families, periods (the horizonal rows) and groups (the vertical columns).

Rayleigh thought this was because of a light impurity in the chemically produced nitrogen, but Ramsay believed there might be an unrecognised new element in the air. The periodic table devised by ...

The table has expanded since Mendeleev’s time, with 50 elements discovered in the 19th century. There are now known to be 118 in total, with the last four formally added in 2016.