So far we are at element 111 so I bet the latest ones aren’t on the periodic table in your school. Currently they are getting less and less stable so thatthe last few have only been detected by their decomposition products but it is though that if scientists can get to the next electron shell, they may start to get less unstable so we may be able to keep going for while.
We can only find bigger ones now… and we can only make them ourselves, not discover them naturally. Once elements get over a certain size, they become unstable, like Laurence has said. So we might be able to make new ones they would only exist for a very short time – like a huge tower of cards! 🙂