. . "An atom becomes an ion if it gains a charge, either positive or negative. It does so by losing (becomes positive) or gaining (become negative) electrons in its outermost electron shell. (Which is also why noble gases rarely have a charge)"@en . "How does an atom become an ion"@en . "An atom becomes an ion if it gains a charge, either positive or negative. It does so by losing (becomes positive) or gaining (become negative) electrons in its outermost electron shell. (Which is also why noble gases rarely have a charge)"@en .