Consider a hydrogen atom in the ground state. What is the energy of its electron? Now consider an excited‑state hydrogen atom. What is the energy of the electron in the =3 level?

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

In apex! a liquid heated beyond a certain temperature becomes

What can be found in the ionosphere