The discovery of other elements followed regularly and soon it became necessary to arrange them in some sort of order ... line in the diagram of the periodic table above separates the metals ...

But how many of these elements do you know? Test your knowledge and compete with other Live Science readers to see who can ...

The modern periodic table is based closely on the ideas he used. Cal: And how is it ordered? Mrs Roberts: So, the elements are arranged in order of increasing atomic number. The horizontal rows ...