* Nitrate ion is a polyatomic ion with the formula NO₃⁻. It has a charge of -1.

* Mg²⁺ is the symbol for the magnesium ion, which has a charge of +2.

You can combine these two ions to form a compound, magnesium nitrate, with the formula Mg(NO₃)₂. This formula ensures that the overall charge of the compound is neutral (2+ from magnesium and 2- from two nitrate ions).

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