(1) Give electronic configuration of the following species and show which of these contain same number of electrons: Cl^(-),N^(3-),P^(3-),K^(+),Na^(+),Mg^(2+),Ar,S^(2-),Ne,O^(2-),Al^(3+),Ca^(2+). (2) In an atom of an inert gas, the difference between the number of p-electrons and s-electrons is equal to the number of d-electrons present in that atom. identify the inert gas and indicate its atomic number.

(1) Give electronic configuration of the following species and show wh

1.	(1) Give electronic configuration of the following species and show which of these contain same number of electrons: Cl^(-),N^(3-),P^(3-),K^(+),Na^(+),Mg^(2+),Ar,S^(2-),Ne,O^(2-),Al^(3+),Ca^(2+). (2) In an atom of an inert gas, the difference between the number of p-electrons and s-electrons is equal to the number of d-electrons present in that atom. identify the inert gas and indicate its atomic number.
Answer» SOLUTION :(1) So, `N^(3-),Na^(+),Mg^(2+),O^(2-)Ne,Al^(3+)` have the SAMME number of electrons (10), so they are isoelectronic. Electronic configuration of each of them `1S^(2)2S^(2)2p^(6)`. Again, `Cl^(-),P^(3-),K^(+),Ar,S^(2-)` and `Ca^(2+)` have the same number of electrons (18), so they are isoelectronic. their electronic configuration is: `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)` (2) The inerrt gas is krypton (Kr) whose atomic number is 36, has electronic configuration: `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)3d^(10)4S^(2)4p^(6)` Total number of s-electrons=8 and total number of p-electrons=18 `therefore`Difference in the number of s and p- electrons `therefore`Difference in the number of s and p-electrons=18-8=10=number of d-electrons.