Lecture Notes Structure of Matter: Atoms and Molecules; W. Ubachs

Application of the old Bohr model

Hn RnZE 2

21. To the hydrogen atom and one-electron systems

2. Application to X-ray or Röntgen spectra

Bremsstrahlung

Characteristic X-rays (atomic levels)

Nuclear transitions

No explanation of the Helium spectrum

Lecture Notes Structure of Matter: Atoms and Molecules; W. Ubachs

Moseleys analysis of X-rays

22

2 111

if nnRZc

Henry Moseley(1887-1915)

22

2 111

ifeff nn

RZc

fif

eff zZnncR

Z

22 11

Physical mechanism

Lecture Notes Structure of Matter: Atoms and Molecules; W. Ubachs

Moseleys K and L series of X-rays

fif

eff zZnncR

Z

22 11

nf =1 K-series (decay to lowest level)

K series: ni=2K series: ni=3

3/4cRzZ K

8/9cRzZ K

nf =2 L-series (decay to n=2 level)

L series: ni=3L series: ni=4

L series: ni=5

5/36cRzZ L

Empirical: zK =1 and zL=7.4

as a function ofAtomic number Info onPeriodic System