Which of the following is another representation of magnesium nitrate?

Magnesium nitrate is represented by the chemical formula Mg(NO3)2. This formula indicates that one magnesium ion (Mg^2+) is combined with two nitrate ions (NO3^-). The nitrate ion consists of one nitrogen atom centrally bonded to three oxygen atoms, and the overall charge of the nitrate ion is negative one. Therefore, to balance the two negative charges from the two nitrate ions with the positive charge of the magnesium ion, we arrive at the composition Mg(NO3)2.

The other representations listed do not accurately depict magnesium nitrate. For instance, while magnesium nitrite (Mg(NO2)2) is close in structure, it represents a different compound entirely due to the presence of nitrite ions instead of nitrate. The other formulas (MgN2O6 and MgN3O9) do not correspond to magnesium nitrate or any known stable configuration of magnesium with nitrate or nitrite ions. In summary, the accurate representation of magnesium nitrate is clearly shown as Mg(NO3)2, making it the correct answer.