An atom in an excited state temporarily stores energy. If the lifetime of this excited state is measured to be 1.0 x 10^-10 s, what is the minimum uncertainty in the energy of the state in eV?

Strategy

The minimum uncertainty in energy ΔE is found by using the equals sign in ΔEΔt ≥ h/4π and corresponds to a reasonable choice for the uncertainty in time. The largest the uncertainty in time can be is the full lifetime of the excited state, or Δt = 1.0 × 10^-10 s.