Radio

In the chemical table, two unusual elements appear between potassium and calcium. The first of these, gallium, is a bluish-white metal (this can be seen already in its simple compounds). Even further away from it is the element ganium. It is similar to francium, the most radioactive chemical element currently known. However, in the middle between them there is unexpectedly a completely different element, a non-metal, extremely hard. Its name is radium.