when an atom gains an electron it becomes a cation
Best Answer: If an atom gains or loses electrons, it is no longer neutral, so it becomes charged. If it GAINS an electron, it gains an extra -1 charge. If it LOSES an electron, it now has a +1 charge. When an atom loses or gains electrons, it is now called an ion. If it loses an electron, it's called a cation, if it gains an electron, its called an anion.