Characteristic X-rays Moseleys law

White radiation is used in material X-ray radiography (translucence, human body). Its properties were mentioned in Section 6.6.4. We will restrict ourselves in this section to a consideration of characteristic X-rays. 

The X-rays resulting from electron transition from any higher level to a lower level with the principal quantum number = 1 are known as K-series transition to a level with n = 2 are known as L-series and series M, N... describe with n = 3,4. etc. Because of the fact that every level after K is split, the transition L K in particular produces three closely set lines, the most intense being denoted as K i. 

The Z-1 value is the so-called effective atomic number. The point is that one electron kicked out of the K level left a second one untouched. The latter takes part in the screening of the positive nuclear charge by the negative electron charge. 

Moseley s discovery is closely connected with the Bohr atomic model, both being announced in the same year (1913). 

The spectra discussed are produced by inner transitions and are not affected by the valence state and chemically bonded atoms. Therefore the characteristic spectra are the probe of the chemical composition of the material investigated. Analysis of the specimen 

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