Question

The total number of electrons present in all the s orbitals, all the p orbitals and all the d orbitals of cesium ion are respectively :

• A. 8, 26, 10
• B. 10, 24, 20
• C. 8, 22, 24
• D. 12, 20, 22

Answer 1

Answer: (B)

The atomic number of cesium is 55. The electronic configuration of cesium atom is ${}_{55}Cs=1s^2,2s^{2}2p^6,3s^{2}3p^{6}4s^2,3d^{10}$ $4p^6,5s^{2}4d^{10},5p^6,6s^1$ $=1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},$ $4s^{2}4p^{6}4d^{10},5s^{2}5p^6,6s^1$ The electronic configuration of cesium ion will be $C{s}^{+}=1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},$ $4s^{2}4p^{6}4d^{10},5s^{2}5p^6,6s^0$ So, the total number of s electrons = 10 the total number of p electrons = 24 Total number of d electrons = 20