What is the craziest element in the periodic table?

Here's what Wikipedia has to say about Astatine: nobody knows what it looks like and it's probably metallic in appearance. In his book, What If? read more

But if you focus on the periodic table - the way the elements are organized - surely the “craziest” are the lanthanides and actinides. All other elements in the table follow a regular pattern. When you add one electron - move one cell to the right - you’re adding a valence electron to the shell. read more

Magnesium is the eighth most abundant element in the earth’s crust, though not found in nature in its elemental form. It is a Group 2 element, called an alkaline earth metal. Magnesium tarnishes slightly in air, and finely divided magnesium readily ignites upon heating in air and burns with a dazzling white flame. read more