Question
The electronic configuration of gadolinium ( at. no. = 64 ) is
A.
$$\left[ {Xe} \right]4{f^8},5{d^9},6{s^2}$$
B.
$$\left[ {Xe} \right]4{f^7},5{d^1},6{s^2}$$
C.
$$\left[ {Xe} \right]4{f^6},5{d^2},6{s^2}$$
D.
$$\left[ {Xe} \right]4{f^3},5{d^5},6{s^2}$$
Answer :
$$\left[ {Xe} \right]4{f^7},5{d^1},6{s^2}$$
Solution :
$$G{d_{64}} = 1{s^2},2{s^2}2{p^6},3{s^2}3{p^6}3{d^{10}},$$ $$4{s^2}4{p^6}4{d^{10}}4{f^7},5{s^2}5{p^6}5{d^1},6{s^2}$$
$$\,\,\,\,\,\,\,\,\,\,\,\,\, = \left[ {Xe} \right]4{f^7},5{d^1},6{s^2}$$