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54 Cards in this Set
- Front
- Back
The only difference between visible light and radio waves is that
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radio waves have longer wavelengths than visible light.
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Two sets of waves can combine with each other to produce a resultant wave. This phenomenon is called?
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interference
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What do all kinds of electomagnetic energy have in common?
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all have the same speed in a vacuum
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The tendency of light to bend at the edge of an opening is called?
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diffraction
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Which of the following effects demonstrates the wave-nature rather than the particle-nature of light?
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diffraction & interference
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Which of the following lists the various forms of radiation in order of -longest- to -shortest- wavelength?
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visible, ultraviolet, X-ray, gamma rays
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The Moon is about 400,000 km from Earth. About how long would it take a radar signal from Earth to reach the Moon?
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1.3 seconds
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The _____ the frequency of light, the ______are the photons of which it is composed.
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higher, more energetic
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When an electron jumps from an excited state to the ground state in an atom,
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a photon is emitted
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When an atom changes from a lower to a higher energy level, the process is called
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excitation
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Suppose you have a detector that captures 1000 photons with a wavelength of 100 Angstroms each. How many photons would you need to collect in order to have the same total amount of energy if the photons had a wavelength of 20 Angstroms?
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200
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In an atom that absorbs a photon,
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an electron moves to a larger orbit.
an electron moves to a higher energy level. the atom may become ionized. it is possible it will spontaneously change its energy state again soon. |
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Wien's Law
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relates the temperature of a radiating object to the wavelength at which it will emit the most energy.
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When a cool gas cloud intervenes between an observer and a source of light that emits light of all wavelengths, the observer would see..
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an absorption spectrum characteristic of the gas cloud
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Ionization means that an atom..
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loses an electron
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Who discovered that most of the universe is hydrogen?
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Cecilia Payne-Gaposchkin
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Which of the following has the stellar spectral classes correctly ordered from coolest to hottest?
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MKGFABO
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You would expect to find the highest degree of ionization in the atmosphere of
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an O-type star.
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We can measure the temperatures of stars from a study of their
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spectra & colors
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The spectral type of the sun is..
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G
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What quantity has the biggest influence in determining the spectral type of a star?
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surface temperature
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A star whose parallax is 0.1 second of arc is at a distance of
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10 parsecs
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If a star is observed from Earth to have a parallax of 0.25 seconds of arc, what would the parallax be if the star were observed from telescopes in Saturn's orbit, which is 10 times larger?
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10 times larger, 2.5 seconds of arc
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In the Hertzsprung-Russell (H-R) diagram, a star less luminous and hotter than the Sun would be found
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below and to the left of the Sun
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How much more energy does each unit area of a 25,000 K star radiate than a 5,000 K star?
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625 times
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If two stars A and B have the same surface temperature, yet star A has a lower luminosity than star B, then
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A must be smaller than B
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The constellation Gatorius consists of five stars, all of which appear equally bright to the eye. Star A is an O supergiant, B is an M giant, C is an M main sequence star, D is a G main-sequence star, and E is a B white dwarf. Which star is intrinsically the most luminous?
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A
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Into which category do the majority of stars fall?
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main sequence
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The Hertzsprung-Russell diagram is
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a graph of stellar luminosity versus surface temperature
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How do Saturn's rings rotate?
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slowly in the outer regions and rapidly in the inner regions
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Jupiter gives off more energy than it receives from the Sun. What is the source of this excess energy?
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internal heat left over from its formation
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What is Jupiter's Great Red Spot thought to be?
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a violent and long-lived storm, like a cyclone or hurricane
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From the observed densities of the Jovian planets, we infer that they are made primarily of ?
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hydrogen
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What makes it possible for astronomers to calculate the masses of the Jovian planets?
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the presence of moons
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Which of the following quantities determines whether a planet will exhibit seasons?
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axial tilt
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What do astronomers infer about Jupiter from the presence of its magnetic field?
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the presence of a rotating core of liquid metallic hydrogen in the interior.
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Jupiter's Galilean satellites have higher densities than the satellites of the other Jovian planets. We can infer that the Galilean satellites contain more _____ than the satellites of the other Jovian planets.
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rocky silicate materials like the Moon
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Which features characterize Io?
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volcanic flows
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What features characterize Europa?
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an ice-covered ocean of water
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What might you reasonably conclude about the origin of small Jovian satellites that orbit in a direction opposite to the largest satellites?
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they are captured comets
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What features characterize Titan?
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the presence of an atmosphere
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What is at least one reason why rings are thought to be sharp-edged, rather than fuzzy-edged?
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The presence of shepherd satellites
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Which of the following planets would come closest to floating in a giant interplanetary bathtub filled with water?
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Saturn
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Why is the interior of Io so hot?
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Jupiter exerts strong tidal forces on it.
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A friend of yours argues that Pluto is probably an escaped satellite of one of the giant planets. What piece of evidence could you cite that would best argue -against- this idea?
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Pluto has a moon of its own
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Which of the following is -not- characteristic of the terrestrial planets?
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short rotation periods
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Why did proto-terrestrial planets have a different chemical composition than proto-jovian planets?
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High temperatures in the inner solar system made the difference.
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Which one of the following statements concerning comets is correct?
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Comets are observed in all directions on the celestial sphere.
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Suppose you wanted to study objects whose chemical make-up was most like that of the solar system at the time it formed. Thus, you would want to study objects that had undergone the least amount of chemical change. Which one of the following would contain such material and thus be the best to study?
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the comets
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What is the source of particles that impinge on the Earth during a meteor shower?
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material evaporated from and strewn out along the orbits of comets
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Which one of these planets has the most extreme seasonal variations?
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Uranus
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In which of the following characteristics is there NOT a MAJOR difference between Pluto and the Jovian planets?
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distance from the sun
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If a comet has a very eccentric (i.e. very elliptical) orbit and has an orbital period of 1000 years, what is its maximum distance from the Sun?
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200 AU
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What is the Oort cloud?
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A nearly spherical distribution of comets, that have been flung out from the inner Solar system by the Jovian planets
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