What does it mean for something to be ionized? An ionized substance is one that has had electrons added or removed from it, giving it a negative or positive charge, or “ion.” For example, the original element carbon-14 has 2 electrons in its innermost shell and 4 in its outer shell, giving it a total of 6 electrons. However, if the carbon were a +4 ion, it means that it has lost 4 electrons, making it a positive ion.