SOMF. COM liMI'Oli.-lRy ADl'.tXCl.S IX fllYSICS II \M 



known as the L ami .\f levels respectively; the electrons from iluin 

 have more energy left o\er after escaping. Line 8 is due to Kd ix- 

 trarting electrons from the L-level. The electrons ejected from the 

 .\/-level l)y Kfi, and those ejecte<l from the L and the M levels 1)\- Kb, 

 are presumably moving too rapidK" to be received on the plate. At 

 the other end of the s|)ectrum the three lines 1, "2, :5 .ire (hie to electrons 



Fig. 5 



expelled from the L and the .1/ levels by two of the secondary X-ray 

 fre()uencies proceeding froin silver atoms: the /Ca-doublet (not 

 separated) and the /CfJ-linc of silver.' Just below this spectrum. 

 we see the electronic spectrum of tin, in which the lines due to the 

 primary X-rays from the tungsten are arranged like the corresponding 

 lines in the silver spectrum, but displaced towards lower energies, 

 since the levels in the tin atoms are different from those in the silver 

 atom; while the lines due to the secondary X-rays are also repeated 

 from the silver spectrum but with an opposite displacement, for in 

 these cases both the levels from which the electrons are taken and the 

 energies available for taking them out have been changed, \e.\t 

 come the spectra of gold and uraniimi. Each of these elements has 

 more electrons per atom than the previous two (uranium has more 



' Krom the nature of the rearrangements resulting in the A'o anri K0 radiations, 

 it follows that the electrons extmcted by the former from the Xf level have the same 

 speeds (ver>- nearly! as those excited by the latter from the L level; the two fre- 

 quencies acting on the two levels produce three separable lines. 



