Periodic Table Of Spectra FAQ
(Click image to enlarge.)
The Periodic Table is used by scientists as a way to represent the chemical elements in tabular form.
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 Spectra poster has the same layout as that original. However, rather than each cell containing numerical data about an element, each box contains the unique spectrum of that element.
Want a poster of your own? Order at this link.
What is a spectrum?
When a chemical element is heated sufficiently, the electrons surrounding 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 the element’s colorful spectrum.
The exciting thing is that each element has its own unique spectrum. In other words, that 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)
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 use that spectrum to identify the element you were studying.
As an example, astrophysicists determine the composition of a distant star by matching the star's spectra to those captured here on Earth.
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 in your poster empty?
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 has a unique spectrum. Quantum mechanics is used to understand the basis of spectra. (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 spectrum 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 being used. In addition, some spectra lines in the real world may be dimmer or thinner than in our poster.
How did you create this poster?
To create this poster, we used the RSpec Explorer software to display the NIST data. RSpec Explorer is an affordable ($395) gas tube spectrometer designed specifically for physics, chemistry and astronomy educators. It can be used to capture gas tube and other spectra in real-time.
Is it possible to capture spectra in the classroom?
This video shows how you can easily capture spectra of gas tubes in the classroom.
Is it possible for me to capture the spectra of stars?
Yes, you can capture the spectra of stars with just a DSLR or small telescope! Here's how: