But, that number, equal to Planck's constant divided by the product of the speed of light and the electron mass, lies in the X-rays, allowing a wavelength shift to be observed when X-rays strike electrons in, FTP, what effect, whose 1922 discovery corroborated the particle nature of light and won its namesake a Nobel Prize?
Since 0.024 Angstroms is small compared to visible wavelengths, this phenomenon is hard to observe with visible light.  But, that number, equal to Planck's constant divided by the product of the speed of light and the electron mass, lies in the X-rays, allowing a wavelength shift to be observed when X-rays strike electrons in, FTP, what effect, whose 1922 discovery corroborated the particle nature of light and won its namesake a Nobel Prize?
Since 0.024 Angstroms is small compared to visible wavelengths, this phenomenon is hard to observe with visible light.  
Compton effect or scattering (accept "Compton wavelength" early)