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example-quiz - Midterm Quiz 1 Terrestrial Planets Name...

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Student #: _______________ Section:__________________ Part I: Multiple-choice, 20 questions. Use computer coding sheet [20 marks]. 1. 40 K (potassium 40) decays to 40 Ar (argon 40) through nuclear capture of an electron with a half- life of approximately 1.26 billion years. The oldest rocks on Earth show ages of about 4 billion years. If a zircon crystal in these rocks formed 4 billion years ago with 1000 atoms of 40 K, what would we expect the ratio 40 Ar/ 40 K to be within it today if it had not been since melted or otherwise damaged? 1. about 1/1 (ie., equal amounts of 40 Ar and 40 K) 2. about 3/1 (ie., 3X as much 40 Ar as 40 K) 3. about 7/1 (ie., 7X as much 40 Ar as 40 K) 4. almost 0/1 (little or no 40 Ar left) 5. many more than 1000/1 (almost no 40 K left) 2. The oldest minerals on Earth (ie., apart from those that have been brought to Earth by meteorites) are zircons found in sediments in Australia. The oldest of them have been dated by uranium-lead methods to what age? 1. between 3.96 and 4.03 billion years 2. 4.54 billion years 3. about 4.4 billion years 4. 5730 years 5. 13.7 billion years 3. The oldest rocks that we, so-far, know of on Earth are from the Acasta Gneiss complex in the Northwest Territories of Canada. Zircons within these rocks have been dated to what age? 1. about 4.4 billion years 2. 13.7 billion years 3. 5730 years 4. between 3.96 and 4.03 billion years 5. 4.54 billion years 4. The oldest rocks returned from the Moon by the astronauts of the Apollo Mission have been dated using various radioactive decay series to what age? 1. 4.54 billion years 2. 13.7 billion years 3. 5730 years 4. about 4.44 billion years 5. less than 3 billion years 5. von Helmholtz determined that the gravitational potential energy retained as heat by the Sun's original accretion could only account for a lifetime of the Sun at its present rate of energy release of about 20 million years. We know that the Sun must be billions of years old. What process accounts for the Sun's prodigious production of energy? 1. Chemical combination of the carbon in the Sun with oxygen produces most of the energy and consequently forms vast amounts of carbon dioxide (CO 2 ). 2. Fusion processes which “burn” hydrogen ( 1 H) into helium ( 4 He). 3. Helmholtz estimate of the energy available from gravitational potential was far too low. It is the gravitational potential energy that accounts for the energy production. 4. Tidal mixing of the fluids in the Sun's interior produces most of the heat. 5. The freezing of iron in the Sun's inner core is now the main source of energy. Version 1
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This test prep was uploaded on 04/22/2008 for the course EPSC 200 taught by Professor Jensen during the Winter '08 term at McGill.

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example-quiz - Midterm Quiz 1 Terrestrial Planets Name...

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