The bond dissociation energy BDE of the oxygen-oxygen O-O bond in an O2 molecule is approximately 498 kJ/mol. Bond dissociation energy is the amount of energy required to break a bond between two atoms in a molecule, resulting in the formation of individual atoms. In this case, it is the energy needed to break the O-O bond in an O2 molecule to form two separate oxygen atoms.The bond dissociation energy is directly related to the strength of the bond between the two oxygen atoms. A higher bond dissociation energy indicates a stronger bond, while a lower bond dissociation energy indicates a weaker bond. In the case of the O2 molecule, the bond dissociation energy of 498 kJ/mol suggests that the O-O bond is relatively strong.The strength of the O-O bond can be attributed to the fact that oxygen atoms have six valence electrons, and they need two more electrons to achieve a stable electron configuration. When two oxygen atoms form a bond, they share two pairs of electrons, resulting in a double bond. This double bond is relatively strong because it involves the sharing of four electrons between the two oxygen atoms, which helps to stabilize the molecule and makes it more resistant to breaking apart.In summary, the bond dissociation energy of the O-O bond in an O2 molecule is approximately 498 kJ/mol, and this energy is directly related to the strength of the bond between the two oxygen atoms. The relatively high bond dissociation energy indicates that the O-O bond is strong, which can be attributed to the double bond formed between the two oxygen atoms.