Periodic Table of Spectra

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Periodic tables have long been used by scientists as a way to represent the chemical elements in tabular form. You can purchase our version of the table at this link.

The first widely recognized periodic table was published by Dmitri Mendeleev in 1869.  His table arrangement, still in use today, illustrates periodic trends and behavior of the elements. (See: https://en.wikipedia.org/wiki/Periodic_table)

Our Periodic Table of the Elements poster has the same layout as the original one from 1869.  However, rather than each cell containing numerical data about the elements, our table contains a spectrum of each element.

What is a spectrum?

When a chemical element is heated sufficiently, the electrons that surround the nucleus may jump from level to level.  When these electrons jump levels, they can release energy, which in some cases can be seen as one or more colors of light mixed together. This light from a “glowing” element can be spread out using a prism, revealing the individual colors that make up element’s colorful spectrum.

The exciting thing is that each element has its own unique spectrum.  In other words, a spectrum is like the fingerprint of an element. For example, the spectrum of copper is different the spectrum of oxygen. (See https://en.wikipedia.org/wiki/Emission_spectrum)

The poster above displays these fingerprints.

 

Frequently Asked Questions (FAQ)

How do scientists use spectra?

Suppose you had an unknown element that you wanted to identify.  In principle, you could heat a small amount of the element, and capture the spectrum by looking at it through a prism. You could then identify the element by comparing your observed spectrum to those on our Periodic Table of Spectra poster. This is how astrophysicists figure out the composition of distant stars.

Where did the data on your poster come from?

Our data source was the US National Institute of Standards and Technology, http://www.nist.gov.

Why are some of the boxes empty in your poster?

Data for these elements was not provided by the NIST because spectra are unavailable. This is generally because the element has a very short half-life, or is synthesized in the lab and exists in conditions that do not allow spectra to be generated.

Why do some of the boxes in your poster have more colored lines than others?

The spectrum that a given element produces depends on the physical properties of that element. Each element differs from the others. The field of quantum mechanics is used to describe the spectra of the elements. (https://en.wikipedia.org/wiki/Quantum_mechanics)

Why don’t some of the spectra in your poster exactly match the spectra I saw in my lab?

The spectra that an element generates varies depending on conditions (temperature, pressure, etc.).  And which specific spectral lines can actually be seen in the lab depends on the type of spectrometer that is used. In addition, some spectra lines in the real world may be more dim or thin than in our poster.  For clarity in our poster, we displayed each line synthesized with a width of 2.5 nm and equal brightness.

How did you create this poster?

We pre-processed the NIST data and then used the RSpec Explorer software to display the data. RSpec Explorer is an affordable ($395) desktop spectrometer for physics, chemistry and astronomy educators.  RSpec Explorer is an excellent companion to our poster. Use it to capture gas tube and other spectra in real-time.  Add a small grating and capture the spectra of stars.

For more information, see our home page: link.

Have additional questions? Contact us: link.

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Above: The RSpec Explorer spectrometer on its tripod.

 

 

 

 

 

 

 

 

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Above: RSpec Explorer viewing a gas tube spectrum.