Question

The electronic configuration of $R{b}^{+}$ in absence of Aufbau Principle, is:

• A. $1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},4s^{2}4p^6$
• B. $1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},4s^{2}4p^4$
• C. $1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},4s^{2}4p^3$
• D. None of these

Answer 1

The correct option is A $1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},4s^{2}4p^6$

According to the Aufbau principle, electrons are filled in the increasing order of (n+l) value.
In the absence of Aufbau principle it wont follow the order of increasing (n+l) value for filling up of electrons .
So, the electronic configuration of $R{b}^{+}$(36 electrons) would be-

$1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},4s^{2}4p^6$.
Hence option (A) is correct.