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73 Cards in this Set
- Front
- Back
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Absolute zero is
a. zero degrees Celsius. b. the temperature at which atoms have no remaining energy from which we can extract heat. c. the temperature at which water freezes. d. both a and c e. none of the above |
b. the temperature at which atoms have no remaining energy from which we can extract heat.
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The neutral hydrogen atom consists of
a. one proton and one neutron. b. one proton. c. one proton, one neutron, and one electron. d. one proton and one electron. e. an isotope and an ion. |
d. one proton and one electron.
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The most massive part of the atom is (are) the _______________ which has (have) a
_____________________charge. a. electrons, negative b. nucleus, negative c. electrons, positive d. nucleus, positive |
d. nucleus, positive
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An atom can be ionized by ________ it.
a. removing electrons from b. adding an electron to c. removing a proton from d. adding a proton to |
a. or b.
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An atom that is excited
a. is also ionized. b. is an isotope. c. has had its electron moved to the lowest energy level. d. can emit a photon when the electron moves to a lower energy level. e. can emit a photon when the electron moves to a higher energy level. |
d. can emit a photon when the electron moves to a lower energy level.
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The ___________ of a gas is a measure of the average speed of the particles in the gas.
a. heat b. composition c. temperature d. blue shift e. binding energy |
c. temperature
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The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight
would an observer see an emission spectrum? a. 1 b. 2 c. 3 d. 2 and 3 e. none of them |
b. 2
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If continuous spectrum light from a star passes through a cool low density gas on its way to your telescope and spectroscope, ___________ spectrum on the continuous spectrum results.
a. a dark (absorption) line b. a bright (emission) line c. continuous |
a. a dark (absorption) line
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If light from a star passes from an excited low density gas seen against the dark background of space to your telescope and spectroscope, ___________ spectrum results.
a. a dark (absorption) line b. a bright (emission) line c. continuous |
b. a bright (emission) line
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Which of the following can be determined by using the Doppler Effect?
I. The speed at which a star is moving away from an observer. II. The transverse velocity of a star. III. The radial velocity of a star. IV. The speed at which a car is traveling toward an observer. a. I & IV b. II & III c. II & IV d. I & III e. I, III, & IV |
e. I, III, & IV
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Most of the visible light from the sun originates in the photosphere.
True or False |
True
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Granulation is caused by rising currents of hot gas below the photosphere.
True or False |
True
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The energy emitted by the sun comes from chemical rather than nuclear reactions.
True or False |
False
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A giant fusion power reactor has been supplying all natural energy to the United States since 1776
True or False |
False
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Sunspots are hotter than the photosphere.
True or False |
False
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Solar flares have no known effect on the Earth.
True or False |
False
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Solar prominences have twisted and looped shapes because of the solar magnetic field.
True or False |
True
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The Sun appears to rotate only because the Earth is revolving about the Sun.
True or False |
False
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The element most abundant in the Sun is oxygen.
True or False |
False
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With the exception of the solar wind, the corona is the outermost region of the Sun’s atmosphere.
True or False |
True
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Parallax would be easier to measure if
a. Earth's orbit was larger. b. the stars were farther away. c. Earth moved slower along its orbit. d. all of these e. none of these |
a. Earth's orbit was larger.
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If a star with an absolute magnitude of -5 has an apparent magnitude of +5, then its distance is
a. 1 pc. b. 10 pc. c. 100 pc. d. 1000 pc. e. 10,000 pc. |
d. 1000 pc.
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Which star in the table above would appear the faintest in the night sky?
a. 65 Tau b. HR 4621 c. Pic d. 58 Ori e. HR 2491 |
a. 65 Tau
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Which star in the table above has the greatest luminosity?
a. 65 Tau b. HR 4621 c. Pic d. 58 Ori e. HR 2491 |
d. 58 Ori
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The _____________ of a star is a measure of the total energy radiated by the star in one second.
a. absolute visual magnitude b. apparent visual magnitude c. luminosity class d. spectral type e. luminosity |
e. luminosity
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Absolute visual magnitude is
a. the apparent magnitude of a star observed from Earth. b. the luminosity of a star observed from a distance of 1000 pc. c. the apparent magnitude of a star observed from a distance of 10 pc. d. the luminosity of a star observed from Earth. e. c and d |
c. the apparent magnitude of a star observed from a distance of 10 pc.
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A star's absolute magnitude depends only on the star's
a. distance and diameter. b. temperature and distance. c. distance. d. temperature and diameter. e. apparent magnitude. |
d. temperature and diameter.
or can be b. temperature and distance (bad question) |
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Which star in the diagram above is most like the sun?
a. Alnilam b. Antares c. Arcturus d. HR 5337 e. Sirius B |
d. HR 5337
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Which star in the diagram above has the greatest surface temperature?
a. Alnilam b. Antares c. Arcturus d. HR 5337 e. Sirius B |
a. Alnilam
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Which of the stars in the diagram above has the brightest absolute visual magnitude?
a. Alnilam b. Antares c. Arcturus d. HR 5337 e. Sirius B |
a. Alnilam
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In an H-R Diagram, stars with the smallest radius are found in the _______ of the diagram.
a. center b. upper left corner c. upper right corner d. lower left corner e. lower right corner |
d. lower left corner
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Binary (double) stars can be detected by
a. being seen as two separate stars with a telescope. b. one star traveling a wiggly proper motion path across the sky. c. one star dimming abruptly as another passes in front of it. d. pairs of absorption lines seen in the spectrum of what appears to be one star. e. all of the above |
e. all of the above
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Stars are born in
a. reflection nebulae. b. dense molecular clouds. c. HII regions. d. the intercloud medium. e. the local bubble. |
b. dense molecular clouds. (called globules)
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The dust in the interstellar medium can make distant stars look redder than they really are.
True or False |
True
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Bok globules are small, dark, spherical fragments of the interstellar medium.
True or False |
True
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HI clouds can be observed using 21-cm radiation.
True or False |
True
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Dark nebulae are produced where dense clouds of gas and dust are silhouetted against regions filled with stars or bright nebulae.
True or False |
True
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Reflection nebulae are produced where very hot stars excite clouds of low density gas to emit light.
True or False |
False, those are emission nebulae
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Emission nebulae are produced when slightly cooler stars illuminate gas clouds around them containing dust
True or False |
False, reflection nebulae
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Certain lines in emission spectra are called forbidden lines because they are never observed in excited gas on
Earth. True or False |
True
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Cool regions of the interstellar medium that emit x-rays are known as coronal gas regions.
True or False |
False, Coronal gas regions are hot, but are very low density
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Protostars are difficult to observe because
a. the protostar stage is very short. b. they are surrounded by cocoons of gas and dust. c. they radiate mainly in the infrared. d. they are all so far away that the light hasn't reached us yet. e. all of the above |
e. all of the above
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Interstellar gas clouds may collapse to form stars if they
a. have very high temperatures. b. encounter a shock wave. c. rotate rapidly. d. are located near main sequence spectral type K and M stars. e. all of the above |
b. encounter a shock wave.
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_____________ are small luminous nebulae excited by nearby young stars.
a. T Tauri stars b. Herbig-Haro objects c. O associations d. WIMPS e. Giant molecular clouds |
b. Herbig-Haro objects
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The diagram to the right is an HR diagram.
The line indicates the location of the main sequence. Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star? a. 1 b. 2 c. 3 d. 4 e. 5 |
d. 4
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The free-fall contraction of a molecular cloud
a. can be initiated by shock waves from supernovae. b. can be initiated by nearby spectral type G stars. c. can be initiated by the rotation of the cloud. d. causes the cloud to become transparent to ultraviolet radiation. e. causes the particles in the cloud to decrease the speed with which they move. |
a. can be initiated by shock waves from supernovae.
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. ______________ is the thermonuclear fusion of hydrogen to form helium operating in the cores of massive stars on the main sequence.
a. The CNO cycle b. The proton-proton chain c. Hydrostatic equilibrium d. The neutrino process e. none of the above |
a. The CNO cycle
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The region of the sun just below the photosphere
a. is undergoing thermonuclear fusion using the proton-proton chain. b. is undergoing thermonuclear fusion using the CNO cycle. c. is transporting energy to the photosphere by convection. d. is not in hydrostatic equilibrium. e. a and c above |
c. is transporting energy to the photosphere by convection.
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What causes the outward pressure that balances the inward pull of gravity in a star?
a. the outward flow of energy due to core fusion reactions. b. the opacity of the gas c. the temperature of the gas d. the density of the gas e. c and d |
a. the outward flow of energy due to core fusion reactions.
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While on the main sequence a star’s primary energy source comes from
a. nuclear fusion. b. nuclear fission. c. gravitational potential energy. d. magnetic fields. |
a. nuclear fusion.
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Which of the following is not considered a component of the interstellar medium?
a. HI clouds b. Intercloud c. Coronal gas d. Molecular clouds e. Water vapor |
e. Water vapor
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Sunspots are dark because
a. regions of the photosphere are obscured by material in the chromosphere b. shock waves move through the photosphere c. the sun rotates differentially d. the strong magnetic field inhibits the currents of hot gas rising from below e. they radiate their energy into space faster than the rest of the photosphere |
d. the strong magnetic field inhibits the currents of hot gas rising from below
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Star clusters are important to the study of stellar evolution because stars in a given cluster have the same
a. temperature b. mass c. age d. luminosity |
c. age
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_____ are small luminous nebulae excited by nearby young stars
a. T Tauri stars b. Herbig-Haro objects c. O associations d. WIMPS e. Giant molecular clouds |
b. Herbig-Haro objects
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To an observer on Earth, dust in the interstellar medium will cause a star to appear
a. brighter and cooler than it really is b. brighter and hotter than it really is c. fainter and cooler than it really is d. fainter and hotter than it really is e. unchanged in brightness or apparent color |
c. fainter and cooler than it really is
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As a star begins to form the initial energy source is from
a. nuclear fusion b. nuclear fission c. gravitational potential energy d. magnetic fields |
c. gravitational potential energy
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What is the order of star colors with increasing temperature?
a. Red, Yellow, Blue b. Blue, Red, Yellow c. Red, Blue, Yellow d. Yellow, Red, Blue e. Blue, Yellow, Red |
a. Red, Yellow, Blue
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Radiation with a wavelength of 21-cm is produced by
a. the hot gas of the interstellar medium b. HI regions c. molecular hydrogen d. emission nebulae e. b and d |
b. HI regions
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Granulation is caused by
a. sunspots b. rising gas below the photosphere c. shock waves in the corona d. the solar wind flowing away from the corona e. the heating in the chromosphere |
b. rising gas below the photosphere
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Which force(s) are responsible for the collapse of an interstellar cloud?
a. nuclear b. gravity c. electric d. magnetic e. Both c and d |
b. gravity
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The sky appears blue during the day because
a. small dust particles in the atmosphere absorb blue light less efficiently than red light b. small dust particles in the atmosphere scatter blue light more efficiently than red light c. the atmosphere contains a large amount of water vapor which, in large quantities, appears blue d. 70% of Earth's surface is water and its blue color is reflected off small particles in the atmosphere e. the ozone in the atmosphere absorbs ultraviolet light and passes more red light than blue |
b. small dust particles in the atmosphere scatter blue light more efficiently than red light
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What are the three layers of the Sun's atmosphere, in order of increasing distance from the surface?
a. Corona, chromosphere, photosphere b. Photosphere, corona, chromosphere c. Photosphere, chromosphere, corona d. Chromosphere, photosphere, corona |
c. Photosphere, chromosphere, corona
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The two most abundant elements in the sun are
a. nitrogen and oxygen b. hydrogen and helium c. sulfur and iron d. carbon and hydrogen e. carbon and nitrogen |
b. hydrogen and helium
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The process of removing an electron from a stable nucleus is known as
a. ionization b. Doppler broadening c. collisional broadening d. a red shift e. quantum mechanics |
a. ionization
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_____ are small dark nebulae less than 1 parsec in diameter that contain 10 to 100 solar masses
a. HI regions b. HII regions c. Emission nebulae d. Bok globules e. Reflection nebulae |
d. Bok globules
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Table 7-2 lists spectral types for each of five stars. Which star in this table would have the lowest temperature?
a. For b. o Cet c. 35 Ari d. Tri e. Per |
b. o Cet (spectral type M7, from hottest to coldest O,B,A,F,G,K,M)
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The location of a star in the HR diagram indicates its temperature and intrinsic brightness
True or False |
True
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The most common kinds of stars are low-luminosity stars
True or False |
True
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The Sun's solar wing fills the Solar System extending well beyond the orbit of Neptune.
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True
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The Maunder Minimum in solar activity coincided with a period of very warm weather all over the Earth.
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False
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Hydrogen is the most abundant element in the Universe.
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True
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If two galaxies collide it is highly unlikely that any two stars in either of the two galaxies will collide.
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True
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Brown Dwarfs are very small objects that can't generate hydrogen fusion.
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True
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