The K series of X-rays consists of photons emitted when an electron drops from the nth Bohr orbit to the first (n − 1). (a) Use (5.33) to derive an expres- sion for the wavelengths of the K series. [This will be approximate, since (5.33) ignores effects of screen- ing.] (b) Find the wavelengths of the Ką, KB, and Ky, lines (n = 2, 3, 4) of uranium. (For the atomic num- bers of uranium and other elements, see the periodic table inside the back cover or the alphabetical lists in Appendix C.) 1 orhit