Atomic numbers of elements A,B and C are 10,13, & 17 respectively. (1) Write their electronic configuration rations.
(2) Which one of them will form cation and which one an atnion?.

Explanation

(1) Electronic configuration of `""_(10)A:1s^(2)2s^(2)2p^(6)`
Electronic configuration fo `""_(13)B:1s^(2)2s^(2)2p^(6)3s^(2)3p^(1)`
Electronic configuration of `""_(17)C:1s^(2)2s^(2)2p^(6)3s^(2)3p^(5)`.
(2) The element, A belonging to group 18, is an inert gas. so it will form neither a cation nor an anion. the element B, belonging to group 13, is a metal. it will radily form a cation by the loss of 3 electrons from its valence shell (3rd shell). the element C will readily gain one electron in its outermost 3rd shell to attain inert gas electronic configuration `(1s^(2) . . . . .3s^(2)3p^(6))`, So, C will form an anion.