Question

The atomic number of $Ni$ and $Cu$ are $28$ and $29$ respectively. The electronic configuration $1s^{2},\,\,2s^{2},\,\,2p^{6},\,\,3s^{2}\,\,3p^{6}\,\,3d^{10}$ represents

• A. $Cu^{+}$
• B. $Cu^{2+}$
• C. $Ni^{2+}$
• D. $Ni$

Answer 1

Answer: (A)

Electronic configuration of
${}_{28} Ni =1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{8}, 4 s^{2}$
$Ni ^{2+} =1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{8}, 4 s^{0}$
${ }_{29} Cu =1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{10}, 4 s^{1}$
$Cu ^{+} =1 s^{2}, 2 s^{2} 2 p^{6}, 3 s^{2} 3 p^{6} 3 d^{10}, 4 s^{0}$
So, the given configuration is of $Cu ^{+}$.