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 2, 8, 8

Answer

c

Explanation

`(8-2)/(8 - X) = 1/1`
`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`