CaBr has bcc structure edge length `4.3 Å.` The shortest inter ionic distance in between `Cs ^(+) and Br ^(-)` is

Options

A. `4. 3 Å`
B. `7. 44 Å`
C. `1. 86 Å`
D. `3. 72 Å`

Answer

D

Explanation

In BCC structure the cations and anions touch along the body diagonal
`2 ( r _(CS) + r _(Br ^(-))) = sqrt3 xx 4. 3` (Body Diagonal `= sqrt3a`)
`r _(c S) + r _( Br ^(-)) = ( 1 . 7 32 xx 4. 3)/(2) = 3. 72 Å`