question_answer

The electronic configurations of Eu(Atomic No 63), Gd(Atomic No 64) and Tb(Atomic No. 65) are        [NEET - 2016]

A) \[[Xe]4{{f}^{7}}6{{s}^{2}},\text{}[Xe]4{{f}^{8}}\text{}6{{s}^{2}}\]and\[[Xe]4{{f}^{8}}5{{d}^{1}}6{{s}^{2}}\]

B)  \[[Xe]4{{f}^{7}}5{{d}^{1}}6{{s}^{2}},\text{}[Xe]4{{f}^{7}}\text{}5{{d}^{1}}\text{ }6{{s}^{2}}\] and \[[Xe]4{{f}^{9}}6{{s}^{2}}\]

C) \[[Xe]4{{f}^{6}}5{{d}^{1}}6{{s}^{2}},\text{}[Xe]4{{f}^{7}}5d16{{s}^{2}}\]and\[[Xe]4{{f}^{8}}5{{d}^{1}}6{{s}^{2}}\]

D)  \[[Xe]4{{f}^{7}}6{{s}^{2}},\text{ }[Xe]4{{f}^{7}}5{{d}^{1}}6{{s}^{2}}\]and \[[Xe]4{{f}^{9}}6{{s}^{2}}\]