File:Fine hyperfine levels.svg
Summary
<a href="https://en.wikipedia.org/wiki/Fine_structure" class="extiw" title="w:Fine structure">Fine</a> and <a href="https://en.wikipedia.org/wiki/Hyperfine_structure" class="extiw" title="w:Hyperfine structure">hyperfine</a> structure in <a href="https://en.wikipedia.org/wiki/Hydrogen_atom" class="extiw" title="w:Hydrogen atom">hydrogen</a>. The <a href="https://en.wikipedia.org/wiki/Angular_momentum_coupling" class="extiw" title="w:Angular momentum coupling">coupling</a> of the different <a href="https://en.wikipedia.org/wiki/Angular_momentum" class="extiw" title="w:Angular momentum">angular momenta</a> leads to energy level splitting. Not drawn to scale.
The <a href="https://en.wikipedia.org/wiki/electron_spin" class="extiw" title="w:electron spin">electron spin</a> angular momentum, S is coupled to the <a href="https://en.wikipedia.org/wiki/Azimuthal_quantum_number" class="extiw" title="w:Azimuthal quantum number">electron orbital angular momentum</a>, L, to form the <a href="https://en.wikipedia.org/wiki/Total_angular_momentum_quantum_number" class="extiw" title="w:Total angular momentum quantum number">total electronic angular momentum</a>, J. This is subsequently coupled to the <a href="https://en.wikipedia.org/wiki/nuclear_spin" class="extiw" title="w:nuclear spin">nuclear spin</a> angular momentum, I, to form the total angular momentum, F.
The <a href="https://en.wikipedia.org/wiki/term_symbol" class="extiw" title="w:term symbol">term symbol</a> takes the form 2S+1L with the values of L represented by letters (S,P,D,F,G,H,... = 0,1,2,3,4,5,...) so that, for instance, a 2P term represents a state with S=1/2 and L=1.
The single electron in a 1s <a href="https://en.wikipedia.org/wiki/Electron_shell#Subshells" class="extiw" title="w:Electron shell">subshell</a> gives rise to the 2S term. L=0 and S=1/2 can only combine to give J=1/2. This in turn can combine with the nuclear spin, I=1/2, to give total angular momentum F=0,1.
The single electron in a 2p subshell gives rise to the 2P term. L=1 and S=1/2 can combine to give J=1/2 and J=3/2. These can combine with the nuclear spin, I=1/2, to give total angular momenta F=0,1 and F=1,2 respectively.
The hyperfine splitting of the ground 2S state is the source of the 21 cm <a href="https://en.wikipedia.org/wiki/Hydrogen_line" class="extiw" title="w:Hydrogen line">hydrogen line</a>, important in astronomy.
Licensing
Lua error in package.lua at line 80: module 'strict' not found.
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 17:37, 6 January 2017 | 432 × 341 (15 KB) | 127.0.0.1 (talk) | <a href="https://en.wikipedia.org/wiki/Fine_structure" class="extiw" title="w:Fine structure">Fine</a> and <a href="https://en.wikipedia.org/wiki/Hyperfine_structure" class="extiw" title="w:Hyperfine structure">hyperfine</a> structure in <a href="https://en.wikipedia.org/wiki/Hydrogen_atom" class="extiw" title="w:Hydrogen atom">hydrogen</a>. The <a href="https://en.wikipedia.org/wiki/Angular_momentum_coupling" class="extiw" title="w:Angular momentum coupling">coupling</a> of the different <a href="https://en.wikipedia.org/wiki/Angular_momentum" class="extiw" title="w:Angular momentum">angular momenta</a> leads to energy level splitting. Not drawn to scale. <p>The <a href="https://en.wikipedia.org/wiki/electron_spin" class="extiw" title="w:electron spin">electron spin</a> angular momentum, <i>S</i> is coupled to the <a href="https://en.wikipedia.org/wiki/Azimuthal_quantum_number" class="extiw" title="w:Azimuthal quantum number">electron orbital angular momentum</a>, <i>L</i>, to form the <a href="https://en.wikipedia.org/wiki/Total_angular_momentum_quantum_number" class="extiw" title="w:Total angular momentum quantum number">total electronic angular momentum</a>, <i>J</i>. This is subsequently coupled to the <a href="https://en.wikipedia.org/wiki/nuclear_spin" class="extiw" title="w:nuclear spin">nuclear spin</a> angular momentum, <i>I</i>, to form the total angular momentum, <i>F</i>. </p> <p>The <a href="https://en.wikipedia.org/wiki/term_symbol" class="extiw" title="w:term symbol">term symbol</a> takes the form <sup>2<i>S</i>+1</sup><i>L</i> with the values of <i>L</i> represented by letters (S,P,D,F,G,H,... = 0,1,2,3,4,5,...) so that, for instance, a <sup>2</sup>P term represents a state with <i>S</i>=1/2 and <i>L</i>=1. </p> <p>The single electron in a 1s <a href="https://en.wikipedia.org/wiki/Electron_shell#Subshells" class="extiw" title="w:Electron shell">subshell</a> gives rise to the <sup>2</sup>S term. <i>L</i>=0 and <i>S</i>=1/2 can only combine to give <i>J</i>=1/2. This in turn can combine with the nuclear spin, <i>I</i>=1/2, to give total angular momentum <i>F</i>=0,1. </p> <p>The single electron in a 2p subshell gives rise to the <sup>2</sup>P term. <i>L</i>=1 and <i>S</i>=1/2 can combine to give <i>J</i>=1/2 and <i>J</i>=3/2. These can combine with the nuclear spin, <i>I</i>=1/2, to give total angular momenta <i>F</i>=0,1 and <i>F</i>=1,2 respectively. </p> The hyperfine splitting of the ground <sup>2</sup>S state is the source of the 21 cm <a href="https://en.wikipedia.org/wiki/Hydrogen_line" class="extiw" title="w:Hydrogen line">hydrogen line</a>, important in astronomy. |
- You cannot overwrite this file.
File usage
The following page links to this file: