Given that interionic distance in Na^(+), F^(-) crystal is 2.31 Å and r_(F^(+)) = 1.36 Å, which of the following predictions will be right

Given that interionic distance in Na^(+), F^(-) crystal is 2.31 Å and

1.	Given that interionic distance in Na^(+), F^(-) crystal is 2.31 Å and r_(F^(+)) = 1.36 Å, which of the following predictions will be right
Answer» `r_(Na^(+))//r_(F^(-)) ~~ 0.7` coordination number of `Na^(+)` = coordinatin number of `F^(-) = 6` `Na^(+), F^(-)` will have ROCK SALT type crystal structure EFFECTIVE nuclear charge for `Na^(+) and F^(-)` are equal Solution :`Na^(+) " & " F^(-)` are isoelectronic hence they will have same screening const (s) but not the effective nuclear charge `:. R_(Na^(+))//r_(F^(-)) ~~ 0.7` (coordination = 6, rock structure)