question_answer

Number of unpaired electrons in\[M{{n}^{4+}}\]is :

A)  3                                            

B)  5

C)  6                                            

D)  4

Correct Answer: A

Solution :

                 The electronic configuration of \[Mn(25)=1{{s}^{2}},\text{ }2{{s}^{2}},\text{ }2{{p}^{6}}3{{s}^{2}}3{{p}^{6}},\text{ }3{{d}^{5}},\text{ }4{{s}^{2}}\] The electronic configuration of \[M{{n}^{4+}}(25-4=21)=1{{s}^{2}}\text{ }2{{s}^{2}},\text{ }2{{p}^{6}}\] \[3{{s}^{2}},3{{p}^{6}},3{{d}^{3}},4{{s}^{0}}\] Thus\[M{{n}^{4+}}\]has three unpaired electrons