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