This is a game like Carta or Card game. Youll see the number on the upper side of the monitor like this: "Which has the atomic number 1 ?". Then you have to tap the card on which written the symbol of the element corresponding to number 1. In this case, the correct answer is H, so you have to tap the H card. Then you can get the H card. What you need to do is to get all of the 20 cards as early as possible. But you will lose if you take 3 mistakes. Another merit of this app is that you can learn 20 important elements with fun.