TAKEN FROM HORIZONS 7TH EDITION CHAPTER 6 TUTORIAL QUIZ 1. The difference between radiation and sound is that a. radiation exhibits the Doppler effect, whereas sound does not. b. radiation travels much slower than sound. c. radiation has wavelength and frequency, whereas sound does not. d. sound needs a physical medium through which to travel, whereas radiation does not. 2. Which of the following chemicals is NOT typically found in stars by studying their spectra? a. Calcium. b. Iron. c. Carbon dioxide. d. Titanium oxide. 3. A blue star appears blue because a. Earth's atmosphere emits more blue light than other colors, and "colors" the stars. b. all colors coming from the star except blue are absorbed by Earth's atmosphere. c. it emits more short wavelengths of visible radiation than long wavelengths. d. of the Doppler effect. 4. What characteristic or behavior does an excited atom possess or exhibit? a. It is ionized. b. It may emit one or more photons. c. All of its electrons are in the ground state. d. It exhibits the Doppler effect. 5. Which of the following is TRUE? a. The spectral sequence of stars from cool to hot is MKFGABO. b. An M-type star appears bluish to the human eye or on a photographic plate. c. An F-type star is hotter than a Btype star. d. The black-body radiation curve for the Sun peaks at green-yellow wavelengths. 6. The discovery that each chemical element emits and/or absorbs specific wavelengths of radiation a. none of these choices. Chemical elements absorb/emit radiation at random wavelengths. b. makes the task of determining what chemicals are in stars very difficult. c. is associated with the branch of science called astrophysics. Page 1
d. is referred to as the white-body radiation hypothesis. 7. When an electron jumps between two energy levels, the energy it absorbs or emits a. is at visible wavelengths. b. forms the Balmer series. c. is less than the energy level difference. d. is the same as the energy level difference. 8. The red glow of clouds of gas and dust in space is due to a. light reflected off Earth's atmosphere and refracted to red wavelengths like sunsets. b. a mixture of the Balmer lines of hydrogen. c. the presence of predominantly red stars in the cloud. d. the Doppler effect. 9. When we think of chemical element #2 (Helium), we think of a. the chemical that makes up about 8% of the material in the known universe. b. that chemical with which the Balmer series of spectral lines is associated. c. the number of energy levels that particular atom has. d. the two electrons that are permanently bound in orbit around the nucleus of the atom. answer: a 10. Astronomers determine the chemical elements in a gas cloud by a. identifying the wavelengths of light absorbed or emitted by the gas. b. obtaining the continuous spectrum of the gas cloud. c. detecting the black body radiation of the gas cloud. d. applying the Doppler effect. answer: a 11. Which of the following is NOT true about chemical element #1 (Hydrogen)? a. It makes up about 73% of the mass of the Sun. b. It has one electron permanently bound in orbit around the nucleus. c. It has one proton in the nucleus. d. It is responsible for the red glow of nebulae. 12. In a laboratory, the hydrogen Balmer alpha line has a wavelength of 656.30 nm. A star's spectrum reveals the same line to have a wavelength of 656.50 nm. a. The star must be cooler than the hydrogen in the laboratory. b. The star is moving away from Earth. c. The electrons in the hydrogen atoms in the star have jumped up two energy levels. d. The electrons in the hydrogen atoms in the star have dropped down two energy levels. Page 2
13. The Doppler effect is associated with all of the following EXCEPT: a. determining the speed of motorists on the highway by police officers. b. the change in pitch of a car's horn as it passes a bystander. c. how fast a star is moving away from or toward Earth. d. speed of the change in position of a star on the celestial sphere. 14. Which of the following statements is FALSE? a. An A0-type star is hotter than an A9-type star. b. An A star is hotter than a G star. c. Determining the temperature of a star by using its spectrum takes considerable time. d. The Doppler effect works with both sound and light, even though they are different phenomena. 15. Which of the following statements about atoms is FALSE? a. The number of protons in the nucleus of an atom determines what atom it is. b. Adding an additional neutron to an atom's nucleus does not change the atom significantly. c. An atom can have fewer electrons than it has protons, but it cannot have more electrons than protons. d. Ionization of hair atoms can occur when you run a comb through your hair. 16. Of what general significance is quantum mechanics to science? a. Collisions between particles can be accurately predicted according to the quantum levels of the initial particles. b. There is no such thing as "reality." c. The orbits of electrons can be described in an exact manner. d. At the atomic and subatomic levels, there may be no relationship between cause and effect. 17. Why is the chemical hydrogen given special emphasis in this chapter? a. It is the only atom that can be detected by radio telescopes. b. All of these choices. c. It is the largest atom in the universe. d. 90 percent of all atoms in the universe are hydrogen atoms. 18. Which of the following statements about atoms is FALSE? a. An ionized hydrogen atom is a single proton. b. If a neutron were added to the nucleus of a hydrogen atom, it would become a helium atom. c. Light from a glowing candle is the result of electrons dropping from higher to lower energy levels. Page 3
d. Electrons "prefer" to be in the ground state. 19. From a scientific perspective, when we say that it is "warm" in the room, we are referring to the a. temperature of the air in the room using the Kelvin temperature scale. b. speed at which the air atoms and molecules are striking our skin. c. energy levels that the electrons of the air atoms and molecules are, on the average, occupying. d. amount of infrared radiation present in the room. 20. Which of the following statements about radiation is TRUE? a. Hot objects emit less short wavelength radiation than do cooler objects. b. Ice cubes at a temperature below the freezing point do not emit black body radiation. c. The maximum intensity of radiation emitted by a human body is at infrared wavelengths. d. Solid objects emit black body radiation. Objects composed of gases do not. 21. Which of the following statements regarding radiation is TRUE? a. Any wavelength can get through the "radio window" if it slows down. b. In general, ultraviolet radiation is less harmful than microwave radiation. c. All wavelengths travel at the speed of light. d. Radio wavelengths are shorter than X-ray wavelengths. 22. Radiation that has slightly less wavelength than that of visible light: a. gamma rays. b. ultraviolet. c. infrared. d. X-rays. 23. The type(s) of radiation that easily penetrate through Earth's atmosphere: a. visible and radio and ultraviolet. b. visible only. c. visible and radio and ultraviolet and infrared. d. visible and radio. 24. When you stand outside facing the Sun and "feel" the warmth of the Sun, you are experiencing a. all of the wavelengths of radiation being absorbed by layers of your skin. b. the infrared radiation being absorbed by your skin. c. hot air moving across your skin. d. the visible light of the Sun being absorbed into your skin. Page 4
25. If you obtained a spectrogram of the Sun's photosphere, it would be a(n) spectrum. a. filtergram b. emission c. continuous d. absorption 26. In which of the following situations is the Doppler effect NOT useful? a. Detecting spectroscopic binary stars. b. Determining the parallax angle of a star. c. Studying behavior of material emerging from the Sun's surface from its interior. d. Determining a star's radial motion relative to Earth. Page 5