question_answer

What is effective nuclear charge and the periphery of nitrogen atom when an extra electron is added in the formation of an anion?

A) 1.20                 

B)        2.45                       

C) 3.55                

D) 5.95

Correct Answer: C

Solution :

When an extra electron is added in nitrogen atom, added electron will be screened by five electrons in second orbit \[(2{{s}^{2}}2{{p}^{3}})\] and two electrons in first orbit \[(1{{s}^{2}}).\] Now screening constant, \[\sigma =5\times 0.35\,\]in nth Orbit \[+\,2\times 0.85\]in \[(n-1)\,th\]orbit \[=1.75+1.70=3.45\] \[\therefore \] Effective nuclear charge \[=7-3.45=3.55\]