Answer:
You can find a helpful list of polyatomic ions in a chemistry reference book or on a reputable chemistry website. One recommended website is the Purdue University Online Writing Lab (OWL) Chemistry Resource, which provides a list of common polyatomic ions and their formulas. Other websites that provide lists of polyatomic ions include Khan Academy and ChemLibreTexts. It's important to note that the specific list of polyatomic ions provided in your class may differ from these lists, so it's always a good idea to check with your teacher or textbook for any specific requirements.