Introduction

In the p-block elements, the last (differentiating) electron enters an outer p-orbital, and since a p-subshell can hold at most six electrons across three p-orbitals, this generates six groups, groups 13 to 18, of the periodic table. Compared with the s-block elements studied in the previous chapter, p-block elements show far greater variation in physical and chemical behaviour, because the number of valence electrons — and hence the possible oxidation states and bonding patterns — changes considerably from group to group. This chapter studies three such families in some detail. Group 13, the boron family, contains boron (B, Z=5), aluminium (Al, Z=13), gallium (Ga, Z=31), indium (In, Z=49) and thallium (Tl, Z=81). Group 14, the carbon family, contains carbon (C, Z=6), silicon (Si, Z=14), germanium (Ge, Z=32), tin (Sn, Z=50) and lead (Pb, Z=82). Group 15, the nitrogen family, contains nitrogen (N, Z=7), phosphorus (P, Z=15), arsenic (As, Z=33), antimony (Sb, Z=51) and bismuth (Bi, Z=83).