A few ways to help remember the difference between cation and anion...
Precious little kitty CATS always help you feel PAWSITIVE (while anions make you feel negative - get it?!)
Okay, okay, I had to! Let's try another one though...
cations
See how that "t" sort of looks like a plus sign? Now, whenever you see cation written, the clue is already in the word!
http://www.differencebetween.info/difference-between-cation-and-anion