Copper(II) acetate containing 64Cu is used to study brain tumors. This isotope has a half-life of 12.7 hours. If you begin with 2.5x10-5 g of 64Cu, what mass remains after 63.5 hours

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

Transportation is the largest single source of air pollution in the united states. air pollution can harm the environment and human health. which technology could offer a solution to this problem? mufflers that reduce noise motors that run on electricity tires that improve gas mileage

Calculate the energy required to ionize a hydrogen atom to an excited state where the electron is initially in the n = 5 energy level. report your answer in kilojoules