An aluminum atom can lose 3 electrons on order to have a full outer energy level . what charge does the resulting aluminum ion have ?

It's easier to lose 3 electrons than gain 5 electrons to fill the outer shell. Therefore aluminum atoms will lose 3 electrons so it takes on a +3 charge when it becomes ion. Specifically it would be a cation due to the positive charge. Aluminum can just lose one to form a positively charged ion

the answer is c. nacl