Each element in the periodic table can appear in gaseous form and will produce a series of bright lines unique to that element. Hydrogen will not look like helium which will not look like carbon which will not look like iron Thus, astronomers can identify what kinds of stuff are in stars from the lines they find in the star's spectrum. This type of study is called spectroscopy.
The science of spectroscopy is quite sophisticated. From spectral lines astronomers can determine not only the element, but the temperature and density of that element in the star. The spectral line also can tell us about any magnetic field of the star. The width of the line can tell us how fast the material is moving.
We can learn about winds in stars from this. If the lines shift back and forth we can learn that the star may be orbiting another star. We can estimate the mass and size of the star from this. You will be asked to identify these elements by looking at the light they produce using your spectroscope. The elements in question will be among those featured in Fig. We will also set up a light source which produces a bright spectral line, and ask you to measure the wavelength of this line.
Once you've done this, you can identify the element involved by looking at the table printed on your spectrometer. Finally, you should take the spectroscope home for a week to look at various light sources and sketch their spectra. In each case, classify the type of spectrum continuous, emission, absorption, or mixed and measure the wavelengths of any bright or dark lines you can see.
You should look at:. Use this chart to sketch spectra of different light sources. If you see lines or other features, place them at the appropriate wavelength using the scale, and list the wavelengths you measure. A spectrum. The light -- in this case, from an ordinary light bulb -- has been spread out into different colors. The scales above and below the spectrum will be explained below. Hydrogen : a simple atom with a simple spectrum.
Besides the three lines shown here, you may be able to see another in the blue near nm. Helium : slightly more complex than hydrogen, with one yellow line and a number in the blue. Neon : a very large number of lines in the red give neon signs their distinctive pink colors, but notice the two green lines. Argon : the pastel color of argon is due to a wide range of lines throughout the spectrum. Mercury : the strongest line, at nm, gives mercury a greenish color.
Energy levels horizontal lines , and downward jumps arrows of hydrogen. The wiggly arrows in color represent the photons produced when an electron jumps down from one orbit to another.
Question fb. Why do elements emit colors when heated? Why is the electromagnetic spectrum continuous? Why is the electromagnetic spectrum a transverse wave? Why are atomic spectra of an element discontinuous?
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