Question

what is the net electrical charge on a magnesium ion that is formed when a neutral atom loses two electrons?

Answer 1

Per electron lost an atom gains a +1 charge. Since 2 electrons are lost the magnesium ion has a 2+ charge.

Answer 2

This magnesium ion will have a charge of +2. This is because it retained the same number of protons and neutrons, but the loss of 2 electrons (with negative charge) means that there are now 2 extra protons compared to electrons, and those 2 protons give a net charge of +2.