Question

Researchers have recently learned how to fabricate thin-filmcoatings only a few atoms thick out of alternating layers oftungsten and boron carbide. These coatings are expected to greatlyimprove the x-ray telescopes used in astronomy. What are the twolongest x-ray wavelengths that will reflect at normal incidencefrom a film with a thickness of 1.60nm?

Part A
Please enter the longest x-ray wavelength. ___nm

Part B
Please enter the second longest x-ray wavelength. ____nm