Chapter 6, Problem 51A

Interpretation Introduction

Interpretation:

The pair of elements having similar chemical properties is to be identified.

Concept Introduction :

The periodic table is a columnar structure that organizes different elements into groups based on how they behave. The elements in the periodic table of today are ordered according to the periodic law. The elements are organized in the modern periodic table in increasing order of their atomic number.

Answer to Problem 51A

Option (b) nitrogen and phosphorous

Explanation of Solution

The elements of the same group tend to have similar chemical properties because of similar outermost electronic configurations. Nitrogen and phosphorous belong to group 15 and have the general electronic configuration as shown,

  $n{s}^{2}n{p}^3$

The chemical properties of elements are decided by the outermost shell configuration. As nitrogen and phosphorous have similar electronic configurations, thus both have similar chemical properties.

Conclusion

Option (a) is incorrect because sodium and chlorine belong to different groups.

Option (c) is incorrect as boron and oxygen belong to different groups.