2. Types of Spectra a. Light from a star with a peak wavelength 450 nm passes through a cloud of hydrogen and helium. Draw the plot that you expect your instruments to measure from this light. 1:). Explain how you drew your plot, including why any parts have an intensity of zero, nonzero. or are morei'less intense than other wavelengths. Hydrogen Helium Note: There are more spectral lines, but these are the ones that your instruments will notice. Intensity 300 400 500 600 700 Wavelength (nm) Plot of Light Intensity vs. Wavelength Helium Emission Spectrum 300 537.4 nm 706.2 nm 250 333.3 nm \\ EST-SQ\" 501.4 nm M O D Intensity (counts) 8 a O D 0| 0 l' | | l I 300 400 300 600 700 300 7L (nm) Explanation of Plot The plot shows the expected light intensity as a function of wavelength for light from a star with a peak wavelength of 450 nm passing through a cloud of hydrogen and helium. Explanation: The intensity ofthe light is reduced at certain wavelengths due to absorption by the hydrogen and helium atoms. Step 2/2 /\\ The following are the reasons for the features in the plot: . Zero intensity at wavelengths 410 nm, 434 mm, and 486 nm: These wavelengths correspond to the Lyman-alpha. Lyman-beta. and Balmer-alpha emission lines of hydrogen. When hydrogen atoms are excited, they can emit light at these wavelengths. However, when light from a star passes through a cloud of hydrogen, the hydrogen atoms in the cloud can absorb light at these same wavelengths. This absorption results in dark lines in the star's spectrum. - Reduced intensity at wavelengths 587 nm and 656 nm: These wavelengths correspond to the helium D1 and D2 emission lines. Helium atoms can also absorb light at these wavelengths, resulting in reduced intensity in the star's spectrum. . Non-zero intensity at all other wavelengths: At wavelengths other than those listed above, there is no significant absorption by hydrogen or helium. Therefore. the light intensity is not reduced at these wavelengths. Explanation: Relative intensities of different wavelengths: The relative intensities of different wavelengths in the plot are determined by the number of atoms in the cloud that can absorb light at those wavelengths. For example, there are more hydrogen atoms than helium atoms in the universe. Therefore, the absorption lines due to hydrogen are more pronounced than the absorption lines due to helium. Final answer A The plot shows the expected light intensity as a function of wavelength for light from a star with a peak wavelength of 450 nm passing through a cloud of hydrogen and helium. The features in the plot are due to absorption by the hydrogen and helium atoms in the cloud. 1. Types of Spectra a. A cool cloud of Helium absorbs light from some nearby stars. You view only the light given off by the cloud, not any stars. Draw the plot that you expect your instruments to measure from this light. b. Explain how you drew your plot, including why any parts have an intensity of zero, nonzero, or are morez'less intense than other wavelengths. Helium Note: There are more spectra! tines, but these are the ones that your Instruments wit! notice. Intensity 300 400 500 600 700 Wavelength (nm) This is an emission spectrum because we only see the light emitted from the Helium gas. This means we only see light at the specific wavelengths that helium absorbs and emits light, which match the emission spectrum shown in the prompt. All other wavelengths of light are absent (dark)