Group 15 elements are also known as nitrogen group elements. Since they only have one valence electron they can give up that electron and become like a noble gas in the cation state. What Is A Functional Groups In Organic Chemistry Digital Kemistry Functional Group Organic Chemistry Chemistry They turn dull grey within a few seconds when they are exposed to air because they. . Iii Lithium shows diagonal relationship with Mg. This group lies in the s block of the periodic table. Iv Alkali metals have lowest ionization enthalpies and largest atomic radii in their. Group 17 of the periodic table consists of fluorine F chlorine Cl bromine Br iodine I and astatine At. This group has lots of variety in the characteristics of their elements. Highly reactive with reactivity increasing moving down the group. Learn vocabulary terms and more with flashcards games and other study tools. These elements have high ioniza...