Physical Geology - Answer Sheet - Test 1 : OnLine Section

Question Answer Comments
# 1 A the universe is thought to have formed 10-15 billion years ago
# 2 C iron and nickel are concenrated in the core
# 3 E

# 4 E the first 4 are examples of some of the problems that scientists work on
# 5 C a hypothesis is an "educated guess" that needs to be tested
# 6 B minerals are naturally occurring, crystalline solids with a fixed OR variable composition
# 7 C
# 8 A
# 9 B
# 10 C the mantle is beneath the crust and above the outer Liquid core
# 11 D see above
# 12 E the Moho discontinuity separates crust from mantle
# 13 B the term crust is used to describe the composition of that part of the Earth whereas lithosphere is used to describe the behavior of that part of the Earth - relatively cold and rigid
# 14 A radioactive decay releases heat - volcanic activity is driven by the accumulation of such heat. the Earth is a poor conductor and it takes heat from the core a LONG time to reach the surface.
#15 B The lithosphere is a rigid solid
# 16 B conduction is a transfer process accomplished as the atoms increase their rate of vibration as the temperature is increased
# 17 D oceanic crust is created at divergent margins or spreading centers
# 18 E oceanic crust has been recycled several times on Earth and consists primarly of basalt which forms at a much higher temperature than the granite which constitutes the continental crust
# 19 B accretion involves addition of material to a continent /// at a divergent margin new sea floor is formed and plates slide past one another at a transform boundary
# 20 D The asthenosphere is hot and plastic and flow can occur
# 21 A about the same rate as finger nails grow
# 22 D Laurasia - the northern hemisphere continents in Pangaea - Gondwanaland - the southern hemisphere continents in Pangaea
# 23 A convergent boundaries can possess a deep-sea trench, shallow, intermediate to deep earthquakes and volcanic activity
# 24 B atomic number - the number of protons in the nucleus : mass number - the number of protons plus neutrons in the nucleus
# 25 C isotopes are atoms of the same element (therefore same number of protons) that differ in mass -- the difference, therefore, is in the number of neutrons
# 26 A ionic bonds involve a transfer of electrons whereas covalent bonding involves sharing electrons
# 27 D the most abundant element in the continental crust is oxygen but oxygen forms anions (has a negative charge). Silicon is the second most abundant element and forms cations (has a positive charge)
# 28 D Tectosilicates involve the sharing of all 4 oxygens per tetrahedron
# 29 A Plagioclase feldspar is the most abundant mineral in the oceanic crust and olivine is the most abundant mineral in the mantle
# 30 E see above
# 31 B Plagioclases cover a significant temperature range. While olivine, pyroxene, amphibole and biotite are precipating as the temperature decreases the plagioclase is becoming enriched in the element sodium - Na
# 32 E rhyolites form by rapid cooling whereas granites form by slow cooling
# 33 C quartz crystallizes about 600 degrees C and is the last rock forming mineral to crystallize from a melt
# 34 B When melts of the composition of oceanic crust are allowed to cool slowly a coarse grained gabbro can form
# 35 A in general, viscosity (the resistance to flow of a liquid or fluid) increases as the temperature decreases. high temperature melts flow easily compared with low temperature melts and gabbro forms at a higher temperature than any of these rocks
# 36 C the other minerals formed at higher temperatures and react more rapidly at the Earth's surface with the reactive atmosphere
# 37 B diamond and graphite are two well known polymorphs - they have identical chemical compostions (both are pure carbon) but differ in structure -- hence the difference in physical properties.
# 38 A with the exception of quartz, all common silicates exhibit solid solution
# 39 D Increasing pressure favors small volumes (material compresses) and smaller volumes mean that the mass is packed more tightly - hence the higher density
# 40 B the longer the time for growth, the larger the minerals tend to be....rapid cooling leads to very small crystals
# 41 A each of the common mineral assemblages forms at a different temperature -- olivine and Ca-rich plagioclase form at high temperatures than alkali feldspar and quartz
# 42 A the Aleutian islands are an island arc - formed where once piece of oceanic crust is subducted beneath another
# 43 B B is a spreading center - formation of new oceanic lithosphere - basalts form at speading centers
# 44 D stratovolcanoes are andesitic - andesitic volcanism accompanies subduction - where a piece of oceanic lithosphere (more dense) is subducted beneath continental crust or oceanic crust
# 45 B a sill is "parallel" to the enclosing structure whereas a dike cuts across the enclosing structure
# 46 B higher temperatures and water promote the rates of chemical reactions
# 47 A Quartz has a density of about 2.6 g/cc - the others are higher
# 48 B the boundary between Europe and Asia
# 49 A where the Juan de Fuca plate is subducted beneath North America
# 50 C within the Pacific Plate

Question	Answer	Comments
# 1	A	the universe is thought to have formed 10-15 billion years ago
# 2	C	iron and nickel are concenrated in the core
# 3	E

# 4	E	the first 4 are examples of some of the problems that scientists work on
# 5	C	a hypothesis is an "educated guess" that needs to be tested
# 6	B	minerals are naturally occurring, crystalline solids with a fixed OR variable composition
# 7	C
# 8	A
# 9	B
# 10	C	the mantle is beneath the crust and above the outer Liquid core
# 11	D	see above
# 12	E	the Moho discontinuity separates crust from mantle
# 13	B	the term crust is used to describe the composition of that part of the Earth whereas lithosphere is used to describe the behavior of that part of the Earth - relatively cold and rigid
# 14	A	radioactive decay releases heat - volcanic activity is driven by the accumulation of such heat. the Earth is a poor conductor and it takes heat from the core a LONG time to reach the surface.
#15	B	The lithosphere is a rigid solid
# 16	B	conduction is a transfer process accomplished as the atoms increase their rate of vibration as the temperature is increased
# 17	D	oceanic crust is created at divergent margins or spreading centers
# 18	E	oceanic crust has been recycled several times on Earth and consists primarly of basalt which forms at a much higher temperature than the granite which constitutes the continental crust
# 19	B	accretion involves addition of material to a continent /// at a divergent margin new sea floor is formed and plates slide past one another at a transform boundary
# 20	D	The asthenosphere is hot and plastic and flow can occur
# 21	A	about the same rate as finger nails grow
# 22	D	Laurasia - the northern hemisphere continents in Pangaea - Gondwanaland - the southern hemisphere continents in Pangaea
# 23	A	convergent boundaries can possess a deep-sea trench, shallow, intermediate to deep earthquakes and volcanic activity
# 24	B	atomic number - the number of protons in the nucleus : mass number - the number of protons plus neutrons in the nucleus
# 25	C	isotopes are atoms of the same element (therefore same number of protons) that differ in mass -- the difference, therefore, is in the number of neutrons
# 26	A	ionic bonds involve a transfer of electrons whereas covalent bonding involves sharing electrons
# 27	D	the most abundant element in the continental crust is oxygen but oxygen forms anions (has a negative charge). Silicon is the second most abundant element and forms cations (has a positive charge)
# 28	D	Tectosilicates involve the sharing of all 4 oxygens per tetrahedron
# 29	A	Plagioclase feldspar is the most abundant mineral in the oceanic crust and olivine is the most abundant mineral in the mantle
# 30	E	see above
# 31	B	Plagioclases cover a significant temperature range. While olivine, pyroxene, amphibole and biotite are precipating as the temperature decreases the plagioclase is becoming enriched in the element sodium - Na
# 32	E	rhyolites form by rapid cooling whereas granites form by slow cooling
# 33	C	quartz crystallizes about 600 degrees C and is the last rock forming mineral to crystallize from a melt
# 34	B	When melts of the composition of oceanic crust are allowed to cool slowly a coarse grained gabbro can form
# 35	A	in general, viscosity (the resistance to flow of a liquid or fluid) increases as the temperature decreases. high temperature melts flow easily compared with low temperature melts and gabbro forms at a higher temperature than any of these rocks
# 36	C	the other minerals formed at higher temperatures and react more rapidly at the Earth's surface with the reactive atmosphere
# 37	B	diamond and graphite are two well known polymorphs - they have identical chemical compostions (both are pure carbon) but differ in structure -- hence the difference in physical properties.
# 38	A	with the exception of quartz, all common silicates exhibit solid solution
# 39	D	Increasing pressure favors small volumes (material compresses) and smaller volumes mean that the mass is packed more tightly - hence the higher density
# 40	B	the longer the time for growth, the larger the minerals tend to be....rapid cooling leads to very small crystals
# 41	A	each of the common mineral assemblages forms at a different temperature -- olivine and Ca-rich plagioclase form at high temperatures than alkali feldspar and quartz
# 42	A	the Aleutian islands are an island arc - formed where once piece of oceanic crust is subducted beneath another
# 43	B	B is a spreading center - formation of new oceanic lithosphere - basalts form at speading centers
# 44	D	stratovolcanoes are andesitic - andesitic volcanism accompanies subduction - where a piece of oceanic lithosphere (more dense) is subducted beneath continental crust or oceanic crust
# 45	B	a sill is "parallel" to the enclosing structure whereas a dike cuts across the enclosing structure
# 46	B	higher temperatures and water promote the rates of chemical reactions
# 47	A	Quartz has a density of about 2.6 g/cc - the others are higher
# 48	B	the boundary between Europe and Asia
# 49	A	where the Juan de Fuca plate is subducted beneath North America
# 50	C	within the Pacific Plate

The average was a 33 or 66%

Use the following scale to give you an idea as to how I would evaluate your performance on this one exam:

84 - 100 : Very Good
70 - 83 : Good
58-69 : OK
50 - 57 : Not So Good
<50 ????