For an electron in a stable orbit of a hydrogen atom, the total energy (E) is related to its kinetic energy (K) by the relationship E = -K. Since the total energy is given as E = -3.4 eV, the kinetic energy is K = -(-3.4 eV) = +3.4 eV. Alternatively, kinetic energy is always positive, and its magnitude equals the magnitude of the total binding energy.