Which reaction below represents the first ionization of o?

Mercury in the environment can exist in oxidation states 0,+1, and +2. One major question in environmental chemistryresearch is how to best measure the oxidation state of mercuryin natural systems; this is made more complicated by thefact that mercury can be reduced or oxidized on surfaces differentlythan it would be if it were free in solution. XPS, X-rayphotoelectron spectroscopy, is a technique related to PES (seeExercise 7.111), but instead of using ultraviolet light to eject valenceelectrons, X rays are used to eject core electrons. The energiesof the core electrons are different for different oxidationstates of the element. In one set of experiments, researchersexamined mercury contamination of minerals in water. Theymeasured the XPS signals that corresponded to electrons ejectedfrom mercury's 4f orbitals at 105 eV, from an X-ray sourcethat provided 1253.6 eV of energy 11 ev = 1.602 * 10-19J2.The oxygen on the mineral surface gave emitted electron energiesat 531 eV, corresponding to the 1s orbital of oxygen.Overall the researchers concluded that oxidation states were+2 for Hg and -2 for O. (b) Compare the energies ofthe 4f electrons in mercury and the 1s electrons in oxygenfrom these data to the first ionization energies of mercuryand oxygen from the data in this chapter.