# $O_2$ undergoes photochemical dissociation into one normal oxygen atom and one oxygen atom, 1.967 eV more energetic than normal. The dissociation of $O_2$ into two normal atoms of oxygen requires 498 KJ$mol^{-1}$.what is the maximum wavelength effective for photochemical dissociation of $O_2$ ?
$(a)\;1645.3A^{\large\circ}\qquad(b)\;1740.2A^{\large\circ}\qquad(c)\;1545.2A^{\large\circ}\qquad(d)\;1942.3A^{\large\circ}$