Cool chemistry question. Can you answer it?

Question

G, H, and I (ramdom variables) belong to a family of very active metals, all of which react with chlorine to produce salts with the general form XCl. G is a member of the first period to contain 18 elements. H has the highest ionization energy of the group and I has the lowest. What are the elements representing G, H, and I?

Answer 1

G = Potassium
H = Lithium (since hydrogen isn't considered a metal)
I = Francium

Answer 2

OK, they are all XCL so that tells you they are alkali metals group 1A.

The first period to have 18, is Potassium. So G is Potassium.

Ionization energy is highest at the top, lowest at the bottom. So H = Hydrogen, and I = Francium.

Answer 3

sodium :P