Skip to main content
Chemistry LibreTexts

Gas Discharge Tubes

  • Page ID
    221952
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Chemical Concepts Demonstrated

    • Atomic emission spectra
    • Bohr atomic model

    Demonstration

    • Veritical tubes filled with the following gases are excited. What colors do they glow
      Gas Color
      1. Hydrodgen Blue-violet
      2. Helium Pink-orange
      3. Neon Red
      4. Argon Violet
      5. Krypton Lavender
      Gas Color
      6. Xenon Blue
      7. Mercury Vapor Blue-violet
      8. Oxygen Blue-violet
      9. Water Vapor Pink

    Observations

    The tubes glow their respective colors when the Tesla coil connects with them. The video shows the gases in the numerical order presented in the tables above.

    Explanation

    The Tesla coil is an energy source. This energy excites the electrons in the gases to higher energy states. In order to return to the ground state, electrons release excess energy in the form of light. The light is differently colored in each tube because of the different wavelengths of light that must be released in each instance.

    Different elements emit different wavelengths of light to return to their respective ground states, so the tubes' colors are varied. These colors can be used to produce atomic emmision spectra of the elements electrically excited. Using known values of emmision spectra, one can perform a similar discharge test on un unknown gas, gather an emmision spectrum from it, and determine which elements are in the unknown gas.

    Contributors


    Gas Discharge Tubes is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

    • Was this article helpful?