Answer:
Ratio represents the relationship between Na and O is 2:1.
Step-by-step explanation:
Given that for every oxygen ion two sodium ions are needed to balance charge.
1 oxygen ion requires 2 sodium atoms
![O^(2-)+2Na^+\rightarrow Na_2O](https://img.qammunity.org/2019/formulas/physics/high-school/9e294c3y4uoygfgqkxvibstbxzfgtw7sdr.png)
The ratio of oxygen ion to sodium ions is:
![(1)/(2)](https://img.qammunity.org/2019/formulas/mathematics/college/q5zg49mbtfrwobmmahi676fbgez56hhab0.png)
So, on reversing the ratio we will get the ratio of sodium ions to oxygen ions:
![(Na^+)/(O^(2-))=(2)/(1)](https://img.qammunity.org/2019/formulas/physics/high-school/qfcsbh3ezwv82altyyhovg8cyau2lfyceu.png)