# Question #4e131

Aug 10, 2016

A formula unit of an ionic compound describes the relative number and kind of elements making the compound.

#### Explanation:

A formula unit of an ionic compound describes the relative number and kind of elements making the compound.

For example, the formula unit of aluminum oxide is $A {l}_{2} {O}_{3}$.

This means that the aluminum oxide is made from $A l$ (aluminum) and $O$ (oxygen). Moreover, it indicates that every two aluminum ions are attracted by three oxygen ions.