What is the co-ordination number of sodium in `Na_(2)O` ?

Options

A. 6
B. 4
C. 8
D. 2

Answer

B

Explanation

`Na_2O` has antiflourine structure. `O^(2-)` ions constituent a ccp lattice and `Na^+` ions occupy the tetrahedral viods, each `O^(2-)` ion is contact with `8Na^+` ions and each `Na^+` ion in contact with `4O^(2-)` ions. Thus C.N. of sodium in `Na_2O=4`