Introduction

In Std. XI we learnt that in the p-block elements the differentiating electron — the last filling electron — enters the p-orbital of the outermost shell. A p-subshell can accommodate a maximum of six electrons, which is why the p-block spans groups 13 to 18 of the periodic table. In this chapter we study the properties of the elements of the last three of these columns: groups 16, 17 and 18 — the oxygen family, the halogen family and the noble gases.