PLEASE HELP!!!!!!!!!!!!!!!!!! Oxygen is in the 16th period, and should therefore have a 2- charge. peroxide also has a charge of 2-(with two oxygens... meaning they each have a charge of 1-??). Are they supposed to have the same charge? Specifically in reference to peroxide(H2O2) becoming water and oxygen(h2O+O), does the remaing one oxygen have a -2 or -1 charge?