A spinel is an important class of oxide consisting two types of metal ions with the oxide ions arranged in ccp layers . The normal spinel has one -eight of the tetrahedral holes occupied by one type of metal ions and one- half of the octahedral holes occupied by another type of metal ion. Such a spinel is formed by `Mg^(2+), Al^(3+) and O^(2-)` . The neutrality of the crystal is being maintained.
The formula of the spinel is :

Options

A. 1
B. 2
C. 3
D. `3//4`

Answer

A