Hey, So I've got a homework question which is gradually transforming by brain in to mashed potato! Here it is.. Identify which of the following compounds contains ions and state the formal charges on the ions: NaCl, N2, MgO, AlCl3, and CO2. Now, I'm not asking for someone to come in and give me the answer to all of them, I'm just after how I can find the answers, I just don't understand after a long time Googling.. I've had a crack and found that NaCl is ionic, but I just don't understand how to figure out the formal charge.. I'm at a loss, any help will be great - thank you!