Question

In a simple model of a neutral magnesium atom with the elements most common mass number. What must happen to an atom of magnesium in order to become a magnesium ion MG^+2 ? Does it lose two electrons and become an ion? or does it lose two neutrons and become a different isotope?

Answer 1

It loses two electrons to become an ion.

(As Neutrons carry no charge changing them would not effect the atom so that's how you know it's the electron :) )