There are seven isotopes of mercury (Hg) with Hg-202 being the most abundant (29.86%).
mercuric sulfate
Mercury (I) Sulfide
Mercury Oxalate
Mercury Sulfide
Mercury(I) sulfite
This formula, if the compound exists, is the formula for mercury(I) peroxide. The formula for mercury(II) peroxide would be HgO2.
The formula for mercurous peroxide is Hg2O2.
Mercurous has a charge of +2, and Oxide has a charge of -2. You cross the chargesand get Hg2O2. The 2s cancel out, leaving you : HgOnuh uh, mercurOUS has a charge of +1, so it's Hg2OmercurIC has a charge of +2, that would be HgO
Mercury peroxide contains a distinct peroxide ion, with the formula O2-2. An oxide ion, in contrast, has a single oxygen atom but also has a charge of -2. The term dioxide, with ionic compounds, is reserved for compounds containing two oxide ions per molecule.