Question

The simple model below is a neutral magnesium (Mg) atom with the element’s most common mass number.

A purple circle labeled M g sits at center with 3 concentric black lines around it. The inner line has 2 small green balls on it. The middle line has 8 small green balls on it. The outer line has 2 small green balls on it.

What must happen to an atom of magnesium in order to become a magnesium ion Mg+2?

It must lose two neutrons and become a different isotope.
It must gain two neutrons and become a different isotope.
It must lose two electrons and become an ion.
It must gain two electrons and become an ion.

Answer 1

It must lose two electrons and become an ion.

Explanation: Neutral Mg has 12 protons and 12 electrons. Losing two negatively charged electrons leaves a net +2 charge (Mg2+). Neutrons (isotopes) are unrelated to ion charge.