The difference in the number of elelctrons between K, L and L, M shells in the same for an atom of element 'X' (M shell is the valence shell) and the difference value is the number of valence electrons in M shell of the other element 'Y' . Give the electronic configurations of their stable ions.

Options

A. 2 , 8 , 2 and 2 , 8 , 6
B. 2 , 8 and 2 , 8
C. 2 , 8 and 2 , 8 , 8
D. 2 , 8 , 8 and 8 , 8

Answer

3

Explanation

`{:("(X)",K,L,M,("Y"),K,L,M),(,2,8,X,,2,8,6):}`
`(8-2)/(8-X)=(1)/(2)`
`8-X=8-2`
`X=2`
Stable ion of X is `X^(+2)` and of Y is `Y^(-2)`.
`X^(+2): 2 ,8 " " Y^(-2):2,8,8`