GROUP 15 NITROGEN FAMILY

It has already been emphasized that within a family of non transition elements, metallic character increases with increase in atomic number, atomic weight, and atomic size. There is no better illustration of this trend than Periodic Group Vb the lightest members of the group, nitrogen (Z = 7), and phosphorus (Z — 15), are typical nonmetals, whereas the heaviest member, bismuth (Z = 83) is a typical metal. The remaining members, arsenic (Z = 33) and antimony (Z 51) are intermediate in character and are often appropriately called metalloids. 

Nitrogen is the first member in Group 15 (VA) of the periodic table. The periodic table is a chart that shows how chemical elements are related to one another. Nitrogen is in a family group named after itself Other elements in the nitrogen family are phosphorus, arsenic, antimony, and bismuth. 

Bismuth, Bi, the 83rd element of the periodic table is the most metallic and the least abundant of the elements in the nitrogen family (group 15). It has an atomic mass of 208.980 and a ground state electronic configuration of [Xe] 4f 5d %s 6p. The bismuth atom usually utilizes the three 6p electrons in bond formation and retains the two 6s electrons as an inert pair, hence the oxidation state -1-3 exhibited by bismuth in the vast majority of its compounds. However, a variety of organobismuth compounds can contain the element in the -1-5 oxidation state. Coordination numbers are 2, 3,4, 5 and 6. Bismuth not only has metallic characteristics but also exhibits many properties similar to those of semiconductors and insulators. Consequently, it is often classified as a semi-metal or metalloid. Bismuth compounds are usually colorless unless the metal is bound to a chromophore. 

The uniqueness of bismuth is most characterized by its low toxic nature in spite of its heavy metal status in the nitrogen family, since it is a general trend of elements that the toxicity increases as you go down a group. Hence traditionally, it has been used widely in medicine and veterinary practice. Closely related arsenic and antimony compounds are generally highly toxic. LD50 (mg/ kg) values of bismuth oxychloride (BiOCl) and bismuth oxide are reported to be 22 000 (rat, oral) and 10 000 (mouse, oral), respectively. Accidental... 

Like nitrogen, phosphorus is a member of the Group 5A family in some respects the chemistry of phosphorus resembles that of nitrogen. Phosphorus occurs most com-... 

The Group VA is the nitrogen family. The group consists of nitrogen, phosphorus, arsenic, antimony, and bismuth. Nitrogen is a diatomic, colorless, and odorless gas, and is not a very reactive element. The Group VA elements have a valence shell configuration of os np ... 

Like nitrogen, phosphorus is a member of the Group 5A family in some respects the chemistry of phosphorus resembles that of nitrogen. Phosphorus occurs most commonly in nature as phosphate rocks, which are mostly calcium phosphate, Ca3(P04)2, and fluoroapatite, Ca5(P04)3p (Figure 21.8). Elemental phosphorus can be obtained by heating calcium phosphate with coke and silica sand ... 

Group 5 The nitrogen family from nonmetalhc nitrogen and phosphorus to metallic bismuth. All have five electrons in the outer shell, and stable inner shells. Group 6 The oxygen family—from oxygen to metallic polonium. All have six electrons in the outer shell, and stable inner shells. 

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