There was always that group of elements set off on their own because they didn't easily fit onto the laminated wall poster hung somewhere ... Low commission rates start at $0 for U.S. listed ...

and atoms of group 2 elements have two electrons in their outer shell. Elements in groups 6, 7 and 0 are non-metals. Atoms of group 7 elements have seven electrons in their outer shell ...

For example, all the elements in group 1 are reactive metals, and all the elements in group 0 are unreactive non-metals. The zigzag, staircase, line in the diagram of the periodic table above ...