For the element barium, which wavelength of light is produced by the largest energy drop of an electron? Which wavelength is produced by the smallest drop? Explain the answer. Make a general statement on wavelength and energy that applies to all the elements.

For such calculation, we apply Planck's equation:

E = nhc / λ; where n is the number of photons, h is the Planck's constant, c is the speed of light and λ is the wavelength of the light.

As is visible from the equation, energy and wavelength have an inverse relationship. Therefore, larger energy drops produce smaller wavelengths and smaller drops produce larger wavelengths.