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29 Cards in this Set
- Front
- Back
If a radioactive isotope were injected into your bloodstream, how many half-lives would youhave to wait before the amount of this isotope in your body is 1/16 its original amount? |
4 |
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A sunspot is a region on the surface of the sun that is ________ the photosphere of the sun. |
cooler and dimmer in visible light than |
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What could happen in planetary systems where the nebular gas is quickly disbursed? |
Large ice-rich planetesimals would not be able to gather hydrogen and helium andbecome gas giants. |
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If Earth had originally formed with less mass, it would likely have have a __________atmosphere and ____________ temperatures compared to now. |
thinner; cooler |
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The carbon dioxide in Earth’s atmosphere is cycled back down into the mantle by |
plate tectonics. |
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Which of the following is not a piece of evidence supporting the idea that Europa may havea subsurface ocean? |
Europa has a magnetic field that appears to respond to Jupiter's magnetic field |
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Approximately what is the core temperature of the Sun that allows hydrogen fusion? |
10 million K |
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What two physical processes balance each other to create the condition known asgravitational equilibrium in stars? |
gravitational force and outward pressure |
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Eta Aurigae is a star with an apparent magnitude of m = +3.2, and is located 75 parsecsfrom Earth. The absorption lines in Eta Aurigae's spectrum are slightly redshifted, indicatingthat Eta Aurigae is: |
moving away from Earth |
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Fusion requires high temperatures in order for nuclei to move quickly enough to:A. overcome gravity |
overcome electrostatic repulsion |
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Earth has fewer impact craters than the moon because of |
its atmosphere |
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Compared to the oldest surfaces on Mercury, the more recently developed surfaces have___________ craters |
fewer |
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Which method could detect a planet in an orbit that is face-on to the Earth? |
astrometric (or “wobble”) method |
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The planet in our solar system with the highest average surface temperature is _________. |
Venus |
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5. How do scientists estimate how old the solar system is? |
They measure the abundances of radioactive elements in meteorites, and use theirhalf-lives to calculate the age. |
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6. Imagine another solar system, with a star of the same mass as the Sun. Suppose a planetwith a mass twice that of Earth (2 MEarth) orbits at a distance of 1 AU from the star. What isthe orbital period of this planet? |
1 year |
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When we say that jovian planets contain significant amounts of hydrogen compounds, wemean all the following chemicals except _________. |
carbon dioxide |
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How do we know the mass of Jupiter? |
by measuring the periods and sizes of the orbits of the moons around Jupiter |
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Which of the following discoveries would cause us to re-evaluate the nebular theory forforming planets? |
A star's 5 terrestrial planets orbit in the opposite direction of its 3 jovian planets |
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Which of the following statements about the accelerations and gravitational forces betweena planet and a star is true? |
Forces are equal and opposite; the planet is accelerated more than the star. |
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. If the freezing point of ices of all types were at a much lower temperature, what changewould that imply for the formation of our solar system? |
The gas giants would have to form at a larger distance. |
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Pluto is different from the Jovian planets in all of the following ways except which one? |
It formed outside of the frost line in the solar nebula. |
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. Which of the following best explains why many jovian moons have been more geologicallyactive than the Moon or Mercury? |
Jovian moons are made mostly of ice that can melt or deform at lower temperaturesthan can the rock and metal that make up the Moon and Mercury |
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Which of the following statements does not lend support to the idea that carbon dioxide is acause of global warming? |
Isotope ratios in atmospheric carbon dioxide show that much of the carbon dioxide inEarth's atmosphere today comes from the burning of fossil fuels. |
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What kind of radiation shines out of the core of the Sun? |
Gamma rays |
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Why is the sky blue? |
Air molecules scatter blue light more than red light. |
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Suppose you could float in space just a few meters above Saturn's rings. What would yousee as you looked down on the rings? |
countless icy particles, ranging in size from dust grains to large boulders |
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9. If Earth passed through the tail of a comet, what would happen? |
A meteor shower would occur. |
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What is the source of Earth's magnetic field? |
Molten metal circulating inside of Earth, moving electrons like in a wire |