The difference in energy levels of an atom can be determined using the following formula:
ΔE = hc/λ
where ΔE is the difference in energy levels, h is Planck's constant, c is the speed of light, and λ is the wavelength of emitted light.
Substituting the given values, we get:
ΔE = (6.626 x 10^-34 J.s) x (2.998 x 10^8 m/s) / (589 x 10^-9 m)
ΔE = 3.37 x 10^-19 J
Therefore, the difference in energy levels of the sodium atom is 3.37 x 10^-19 J.