Geol125 Exam 1

Geol125 Exam 1 - GEOL 125: Sample Exam Questions (Exam I)...

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Unformatted text preview: GEOL 125: Sample Exam Questions (Exam I) I. Multiple Choice Quickies: Read ALL of the choices and choose the letter corresponding to the best one (*read very carefully). Fill in your answer on the Scantron sheet. Do not forget to put your name on the scantron sheet. (25 pts) 1. 2. 3. 4. The fundamental force holding the nucleus together is: a) Weak Force, b) Electromagnetic Force, c) Strong Force, d) Gravitational Force, e) Energy Force. The chemical identity of an atom is determined by: a) number of attached electrons; b) number of nucleons; c) number of protons in nucleus; d) number of neutrons. Electromagnetic radiation can: a) behave like a wave, b) travel at the speed of light, c) be emitted by objects colder than 50K, d) all of the above, e) only a and b. The cosmic background radiation we see today dates from: a) the first instant of the big bang; b) 3 minutes after the Universe formed; c) when the Universe cooled sufficiently that electrons could attach to protons and form neutral hydrogen atoms; d) the formation of our sun. Protons are made of: a) neutrinos, b) quarks, c) gluons, d) leptons; e) dark matter. Binding energy per nucleon is: a) a measure of the relative nuclear stability; b) lowest for Fe-56; c) identical for all stable isotopes; d) dependent on the chemical form of the atom. The periodic table groups elements according to: a) alphabetical order; b) similarities in chemical behavior; c) their nuclear stability; d) the order of element discovery; e) their abundance in the Universe. The distance to far-off galaxies can be estimated from: a) parallax methods; b) their composition; c) their brightness if luminosity is known; d) their rotation rate; e) their color. The model describing solar system formation from a massive dust cloud explains which observation: a) the alignment of planetary orbits in nearly one plane; b) the prograde orbits of planets; c) the density contrasts between inner and outer planets; d) all of the above. The average composition of the solar system has been determined by: a) spectroscopic studies of the sun; b) planet densities, c) analysis of meteorites, d) analysis of earth rocks, e) all of the above. The most abundant element in the Universe is: a) H; b) He; c) O; d) Fe; e) Pb. Our galaxy is: a) a giant elliptical galaxy; b) expanding; c) Andromeda; d) a spiral arm galaxy. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Population II stars are most common: a) in globular clusters above the galactic plane, b) in spiral arms, c) in our solar system, d) between spiral arms. The age of the solar system and the age of the Universe are estimated to be: a) 4.5 by and 14 by; b) 4.5 my and 14 my; c) 200 my and 50 by; d) 1.1 by and 4.5 by Which of the following must be conserved in any interaction: a) energy; b) angular momentum; c) electrical charge; d) both (a) & (c); e) all of the above. II. Quickies: Fill in the blank spaces with the word, number, or phrase that is most appropriate. Give units where necessary. (1 point for each blank) a) The force holding neutrons and protons in the nucleus in called the ______________. b) Similarities in the behaviors of various elements led to their placement in the _________________________ that is used to classify all chemical elements. c) Galactic velocity can be determined from _______________________. d) As an object is heated, two characteristics of the radiation it emits change: ______________________________ and _____________________________________. e) Formation of our solar system is thought to include the following steps: A dust cloud collapses because _____________________________________. As it collapses, it begins to spin rapidly in order to conserve ___________________________. The inner planets are ________________________ than the outer planets because ____________________________________________. What evidence exists that earth material was once part of another star? ____________________________________. f) During fusion, the mass of the products is always ____________(choose less or more) than the mass of the starting materials. The difference is called the ________________. III. Matching: Fill in the blanks by the left column with the letter of the phrase in the left column that is most appropriate. A letter may be used more than once. (1 point for each blank) ____ H ____ He ____ C ____ Si ____ 56Fe ____ 206Pb A. The most stable form of matter B. Is "burned" in the core of red giants C. Shows a valence of +5 D. Is the daughter product of a radioactive parent E. The most abundant form of matter F. Has 6 protons in nucleus G. A radioisotope useful for age dating H) "Burns" explosively IV. Graphs: Draw graphs that show the following. Be sure to label each axis and note whether the scale is linear or logarithmic. (6 points each) a) The Hubble plot for receding galaxies. Briefly explain how this graph can be used to estimate the age of the universe. b) A Hertzsprung-Russell diagram. Indicate the positions of main sequence stars, red giants, white dwarfs, supergiants, and our sun. Use a line with arrows to show how a star of solar mass evolves on this diagram. V. Puzzlers: Briefly explain each of the following. You may wish to cite an observation or an equation to explain your answer, although this may not be necessary for some questions. (2 points each) a) Why is a mass of at least 0.1 solar masses necessary for a star to form? b) Last night, a mysterious greenish flash was observed in the northeastern sky. A few other colors were observed in this event, as well. The media suggested this might have been caused by the entry of some satellite debris into our atmosphere, or perhaps a meteorite. Recalling our discussions about spectroscopy, does this seem like a reasonable explanation, and if so, why might the color be green? c) A mineral is found to have 25 atoms of 235U and 75 atoms of its stable daughter 207Pb. If no Pb was present when the mineral formed and the half-life of 235U is 0.7 by, estimate the age of the mineral. Show your reasoning. ...
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