.. _sphx_glr_api_gallery_spectro_atomic:

Atomic line spectra
--------------------

Discrete atomic lines as chemical fingerprints: Fraunhofer's dark solar
lines, Kirchhoff and Bunsen's flame emission and absorption spectra, and
the Balmer-Rydberg formula for the hydrogen series.


.. raw:: html

  <div id='sg-tag-list' class='sphx-glr-tag-list'></div>


.. raw:: html

    <div class="sphx-glr-thumbnails">

.. thumbnail-parent-div-open

.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Fraunhofer (1814) found that sunlight is not a smooth rainbow but a continuum crossed by hundreds of sharp dark lines at fixed, reproducible wavelengths, and he labelled the strongest ones A to K. This example builds a sun-like continuum from Planck&#x27;s law at 5800 K, removes light at the tabulated positions of Fraunhofer&#x27;s lettered lines using narrow Lorentzian absorption profiles, and marks each letter above its line.">

.. only:: html

  .. image:: /api/gallery/spectro/atomic/images/thumb/sphx_glr_plot_01_fraunhofer_dark_lines_thumb.png
    :alt:

  :doc:`/api/gallery/spectro/atomic/plot_01_fraunhofer_dark_lines`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Fraunhofer's dark lines: sharp absorption lines at fixed wavelengths in the solar spectrum</div>
    </div>


.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Bunsen and Kirchhoff (1859-1861) vaporized salts in a nearly colourless flame and found that each element gives bright lines at its own fixed wavelengths. The top panel shows the strongest visible and near-visible resonance lines of the alkali metals they studied, including caesium&#x27;s blue doublet and rubidium&#x27;s red and near-infrared lines, the lines that revealed those two new elements. The bottom panel illustrates Kirchhoff&#x27;s law: a cooler sodium vapour placed in front of a continuous source absorbs at exactly the wavelengths where hot sodium emits. This is what explains Fraunhofer&#x27;s D lines.">

.. only:: html

  .. image:: /api/gallery/spectro/atomic/images/thumb/sphx_glr_plot_02_kirchhoff_bunsen_flame_spectra_thumb.png
    :alt:

  :doc:`/api/gallery/spectro/atomic/plot_02_kirchhoff_bunsen_flame_spectra`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">Kirchhoff and Bunsen's flame spectra: bright emission lines and matching dark absorption lines</div>
    </div>


.. raw:: html

    <div class="sphx-glr-thumbcontainer" tooltip="Balmer (1885) fitted the four visible hydrogen lines with \lambda=B\,n^2/(n^2-4). Rydberg (1890) rewrote this in wavenumbers as \tilde\nu=R(1/n_1^2-1/n_2^2), and Bohr (1913) derived it from quantized electron energies E_n=-hcR/n^2. This example computes the Lyman, Balmer, and Paschen series with rydberg_wavenumber, checks the result against Balmer&#x27;s original formula, and shows each series bunching toward its series limit.">

.. only:: html

  .. image:: /api/gallery/spectro/atomic/images/thumb/sphx_glr_plot_03_balmer_rydberg_hydrogen_series_thumb.png
    :alt:

  :doc:`/api/gallery/spectro/atomic/plot_03_balmer_rydberg_hydrogen_series`

.. raw:: html

      <div class="sphx-glr-thumbnail-title">The hydrogen spectrum: Balmer's formula, the Rydberg series, and Bohr's energy levels</div>
    </div>


.. thumbnail-parent-div-close

.. raw:: html

    </div>


.. toctree::
   :hidden:

   /api/gallery/spectro/atomic/plot_01_fraunhofer_dark_lines
   /api/gallery/spectro/atomic/plot_02_kirchhoff_bunsen_flame_spectra
   /api/gallery/spectro/atomic/plot_03_balmer_rydberg_hydrogen_series