* Magnesium (Mg): Magnesium is in group 2 of the periodic table, meaning it has a +2 charge when it forms an ion.
* Fluorine (F): Fluorine is in group 17 of the periodic table, meaning it has a -1 charge when it forms an ion.
To form a neutral compound, we need two fluoride ions (2 x -1 = -2) to balance the +2 charge of the magnesium ion.
