HS Sample Set 12, Round 14 from NSB
During a solar eclipse, an observer’s view of the Sun is completely blocked by the moon. The observer is therefore standing in what region of the Moon’s shadow?
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Which of the following statements best reflects our current understanding of the past and present of Mars’ atmosphere? W) It has always been about as thick Earth’s atmosphere today X) It has always been much thinner than Earth’s atmosphere today Y) It was thick shortly after formation, but has since thinned due to solar wind Z) It was thin shortly after formation, but has since thickened due to volcanic outgassing
W: W) It has always been about as thick Earth’s atmosphere today
X: X) It has always been much thinner than Earth’s atmosphere today
Y: Y) It was thick shortly after formation, but has since thinned due to solar wind
Z: Z) It was thin shortly after formation, but has since thickened due to volcanic outgassing
Answer: Y) Y) It was thick shortly after formation, but has since thinned due to solar wind
Identify all of the following three terms that can describe the behavior of water: 1) Nucleophile; 2) Lewis base; 3) Bronsted acid.
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Identify all of the following three statements that are true of crystal field theory: 1) d orbitals in a coordinated metal can be higher in energy than in the isolated metal ion; 2) All d orbitals are elevated in energy equally when a metal is coordinated; 3) In a coordinated metal ion, the d orbitals are degenerate.
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DOE scientists working on the Dark Energy Survey at Fermilab serendipitously discovered a potential dwarf planet orbiting the Sun at 92 AU. Which of the following is closest, in Earth-years, to the orbital period of this object? W) 110 X) 1,100 Y) 11,000 Z) 110,000
W: W) 110
X: X) 1,100
Y: Y) 11,000
Z: Z) 110,000
Answer: X) X) 1,100
Researchers supported by Ames Lab have recently provided spectroscopic evidence for a type of material in which the electron and hole bands are connected at Weyl points, which are in turn connected by Fermi arcs. These materials are a specific type of what general group of materials in electronic band theory?
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Which of the following thermodynamic quantities is a path function? W) Energy X) Enthalpy Y) Entropy Z) Heat
W: W) Energy
X: X) Enthalpy
Y: Y) Entropy
Z: Z) Heat
Answer: Z) Z) Heat
A solid uniform cylindrical rod has moment of inertia I when rotating about its center like a propeller. In terms of I, what is the moment of inertia of a second rod of the same density but twice the length, when rotated about its symmetry axis?
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Let f(x) be a continuous and differentiable function on the closed interval [2,6]. Which of the following could be the x-value guaranteed by the mean value theorem for this situation? W) 0 X) 3 Y) 6 Z) 9
W: W) 0
X: X) 3
Y: Y) 6
Z: Z) 9
Answer: X) X) 3
Solve the following equation for x: 4x + 2 = |3x – 5|.
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Identify all of the following three classes that contain organisms that produce amniotic eggs: 1) Reptilia; 2) Aves; 3) Mammalia.
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Which of the following codons could NOT result in a nonsense mutation following a single-nucleotide substitution? W) GGA X) UCG Y) CAA Z) AGG
W: W) GGA
X: X) UCG
Y: Y) CAA
Z: Z) AGG
Answer: Z) Z) AGG
Which of the following is closest to the average density, in grams per cubic centimeter, of Earth’s core? W) 5.5 X) 7.1 Y) 8.9 Z) 12.8
W: W) 5.5
X: X) 7.1
Y: Y) 8.9
Z: Z) 12.8
Answer: Z) Z) 12.8
Which of the following metamorphic index minerals is typically found in the metamorphic facies granulite? W) Chlorite X) Kyanite Y) Andalusite Z) Sillimanite
W: W) Chlorite
X: X) Kyanite
Y: Y) Andalusite
Z: Z) Sillimanite
Answer: Z) Z) Sillimanite
An engineer designs a step-down transformer to convert 240 volts RMS down to 20 volts RMS. If the primary winding has 600 turns, how many turns are required on the secondary winding?
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In volts to the nearest tenth, what is the change in potential from a distance of 3 meters to a distance of 6 meters of a 1-nanocoulomb point charge?
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What gene-editing method relies on synthetic guide RNAs to direct Cas nucleases to target sites for gene editing?
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In a typical mouse mammalian research model, which type of epithelial cell would be most prevalent lining kidney tubules? W) Simple cuboidal X) Simple columnar Y) Simple squamous Z) Stratified columnar
W: W) Simple cuboidal
X: X) Simple columnar
Y: Y) Simple squamous
Z: Z) Stratified columnar
Answer: W) W) Simple cuboidal
What is the largest prime factor of 165?
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What is the standard deviation of the following list of 4 numbers: 7, 7, 9, 17?
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Scientists at Oak Ridge National Lab are simulating the breakdown of lignocellulosic biomass in the presence of tetrahydrofuran, or THF. What purpose does THF serve in this reaction? W) Catalyst X) Solvent Y) Reactant Z) Chaotropic agent
W: W) Catalyst
X: X) Solvent
Y: Y) Reactant
Z: Z) Chaotropic agent
Answer: X) X) Solvent
Identify all of the following three statements that are true regarding thorium: 1) Thorium can be found in nature as one nonfissile isotope; 2) Thorium-232 can undergo neutron capture; 3) Thorium-232 is radioactive with a half-life of 21 minutes.
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A student is interested in the optical properties of chiral molecules, so she successively performs a chlorination, bromination, and an iodination of methane. However, she is disappointed to find out that the resulting product demonstrates no optical rotation of polarized light. Which of the following best explains this? W) She prepared a racemic mixture X) Only certain chiral molecules demonstrate optical rotation Y) Geometric isomers demonstrate optical rotation, not stereoisomers Z) Only larger, more complex chiral molecules demonstrate optical rotation
W: W) She prepared a racemic mixture
X: X) Only certain chiral molecules demonstrate optical rotation
Y: Y) Geometric isomers demonstrate optical rotation, not stereoisomers
Z: Z) Only larger, more complex chiral molecules demonstrate optical rotation
Answer: W) W) She prepared a racemic mixture
Consider the reaction of 1-bromopentane with sodium hydroxide. Which of the following pairs of characteristics apply to this reaction? W) SN1 at low temperatures and E1 at high temperatures X) E1 at low temperatures and SN1 at high temperatures Y) SN2 at low temperatures and E2 at high temperatures Z) E2 at low temperatures and SN2 at high temperatures
W: W) SN1 at low temperatures and E1 at high temperatures
X: X) E1 at low temperatures and SN1 at high temperatures
Y: Y) SN2 at low temperatures and E2 at high temperatures
Z: Z) E2 at low temperatures and SN2 at high temperatures
Answer: Y) Y) SN2 at low temperatures and E2 at high temperatures
In the lac operon, allolactose can be classified as what? W) Repressor X) Inducer Y) Promoter Z) Transcription factor
W: W) Repressor
X: X) Inducer
Y: Y) Promoter
Z: Z) Transcription factor
Answer: X) X) Inducer
In a typical neuron, voltage-gated potassium channels are gated so that they open at what potential, in millivolts? W) –100 X) –70 Y) –30 Z) +40
W: W) –100
X: X) –70
Y: Y) –30
Z: Z) +40
Answer: Z) Z) +40
Point P is one of the vertices of a 42-sided convex polygon. How many diagonals of the polygon have point P as an endpoint?
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Give the parametric equations in terms of t for the line that is parallel to the vector –5i – 6j + 2k and that passes through the point (4, –2, 8).
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Ames Lab researchers have been studying the atomic-scale geometry of platinum ions when they are incorporated into large, porous complexes consisting of metal cations and organic ligands. What is the name for this group of complexes?
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Researchers at Oak Ridge National Lab are studying a bacterial species, present in the GI tract of more than 50% of the world’s population, that is known to cause ulcers and stomach cancer. What is the full genus-species name of this bacterium?
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The Fermi energy of semiconductors lies in which of the following regions? W) Valence band X) Band gap Y) Conduction band Z) Ground state
W: W) Valence band
X: X) Band gap
Y: Y) Conduction band
Z: Z) Ground state
Answer: X) X) Band gap
Alison measures the net charge inside a cell to be −9.0 picocoulombs. Assuming this charge is perfectly enclosed by the cell membrane, what is the magnitude of the flux, to two significant figures and in newton-meters squared per coulomb, through the cell membrane?
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What is the name given to the end moraine that denotes the farthest advance of glacial ice?
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Identify all of the following three eras that belong to the Phanerozoic eon: 1) Paleozoic; 2) Mesozoic; 3) Cenozoic.
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Which of the following atoms has an atomic radius closest to the atomic radius of sodium? W) Beryllium X) Magnesium Y) Calcium Z) Strontium
W: W) Beryllium
X: X) Magnesium
Y: Y) Calcium
Z: Z) Strontium
Answer: Y) Y) Calcium
Arrange the following three classes of organic compounds in increasing order of electrophilicity: 1) Ketone; 2) Ester; 3) Amide.
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What is the dot product of 4i – 7j and 5i + 2j?
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A restaurant has a special that allows you to pick any 2 of 11 possible items, and allows 2 of the same item. How many different orders are possible?
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On the planet Jupiter, what term describes the cooler, dark bands of latitude that correspond to atmospheric downwelling?
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Identify all of the following three statements that are true of cosmic molecular clouds: 1) Hydrogen in molecular clouds is typically present as H2; 2) They contain trace amounts of small organic compounds such as formaldehyde; 3) Constituents of molecular clouds are typically present as ions.
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In order to solve a physics problem, a student calculates the surface integral of the normal component of an electric field over a particular surface area. What physical quantity is the student determining?
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What is the resonant frequency, in radians per second, of a parallel LC circuit with an inductance of 2 millihenries and a capacitance of 80 microfarads?
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P orbitals can form what two types of bonds?
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Identify all of the following three molecules that, according to molecular orbital theory, have non-zero bond orders: 1) H2; 2) He2; 3) He2+.
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In fungal reproduction, what stage is characterized by the haploid nuclei of different parents fusing into a single diploid nucleus?
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Identify all of the following four phyla that possess a segmented body plan: 1) Arthropoda; 2) Mollusca; 3) Nematoda; 4) Chordata.
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