Step 1. Look at the polyatomic ion name at the top of the screen. Try to remember which chemical formula matches to that name. Step 2. Click the purple "flip" button at the bottom of the screen to reveal the answer. Step 3. Click on "hard", "kinda hard", "ok", "easy", and "super easy" depending on how hard it was to answer that question. This will move the current card further down the deck so you will encounter it later to refresh your memory. The easier the question, the farther back the card will move. If you want to refresh the cards, refresh the page and click the green flag again. Keep reviewing until you are confident that you have memorised all the terms. Remember to keep practicing consistently every week to keep it in your mind. Also remember that learning is most fun and productive when done through interactive examples. Only use flashcards when the task specifically demands memorisation.
This is a general flashcards program that I made in case I need to memorise terms for anything. You can go inside the code and change the "queue" and "answers" list to any flashcards set you want.