In the [UO2Cl4]2- complex, the coordination number of Uranium is 6. This is because Uranium is surrounded by 2 oxygen atoms and 4 chlorine atoms, making a total of 6 ligands coordinated to the central metal atom.To determine the oxidation state of Uranium, we can use the following equation:Oxidation state of Uranium U + 2 * Oxidation state of Oxygen O + 4 * Oxidation state of Chlorine Cl = Charge of the complexSince the oxidation state of Oxygen is typically -2 and that of Chlorine is -1, the equation becomes:Oxidation state of U + 2 * -2 + 4 * -1 = -2Oxidation state of U - 4 - 4 = -2Oxidation state of U = +6So, the oxidation state of Uranium in the [UO2Cl4]2- complex is +6.