Ionic radii of `Mg^(2+)` and `O^(2-)` ions are 66pm and 140pm respectively. The type of intersitital void and coordination number of `Mg^(2+)` ion respectively are

Options

A. tetrahcdral, 12
B. octahedral, 6
C. tetrahedral, 6
D. octahedral, 8

Answer

A

Explanation

Radius ratio `(r_(mg^(+2)) )/(r_(O^(2-) )) = 66/140 = 0.47`
Hence `Mg^(2+)` occupies octahedral void