Discussion Forum

1)

The arrangement of X^- ions around A⁺ ion in solid AX is  given in the figure (not drawn to scale ) . If tythe radius of X^- is 250 pm, the radius of A^- is 

Answer:

Option A

Explanation:

Plan  Given arrangement represents octahedral  void and fix this 

                   $\frac{r_{+}(cation)}{r_{-}(anion)}=0.414$

$\frac{r(A^{+})}{r(X^{-})}=0.414$

 $r(A^{+}){}=0.414\times r(X^{-})$

   $=0.414\times250pm=103.5 pm$