mercuric oxide
That name is used as the systematic or common name for a compound. This compound is also known as Mercury (II) oxide due to the oxidation number of a transition metal being used in the IUPAC nomenclature. The compound, Hg2O, would, therefore, be known as Mercury (I) oxide or mercurous oxide.
This formula, if the compound exists, is the formula for mercury(I) peroxide. The formula for mercury(II) peroxide would be HgO2.
Observable or measurable change refers to physical changes in appearance, behavior, or characteristics that can be detected or quantified, such as a person gaining weight or a plant growing taller. These changes do not alter the fundamental identity or essence of the object or individual undergoing the transformation.