The radius of a calcium ion is 94 pm and of the oxide ion is 146 pm. The possible crystal structure of calcium oxide will be

Options

A. tetrahedral
B. trigonal
C. octahedral
D. pyramidal

Answer

C

Explanation

As per formula,
radius ratio`=("radius of cation")/("radius of anion")`
`=(94)/(146)=0.643`
Since the value is between 0.414 - 0. 732 hence the
coordination no. will be 6 and geometry will be
octahedral