HS Sample Set 7, Round 5 from NSB
You are given a particular polymer to study, and you notice that it can endure an extremely high amount of stress, but only a very small amount of strain. Which of the following types of polymer is it? W) Brittle plastic X) Tough fiber Y) Elastomer Z) Plastic with yield
W: W) Brittle plastic
X: X) Tough fiber
Y: Y) Elastomer
Z: Z) Plastic with yield
Answer: X) X) Tough fiber
The measured bond angle in ammonia is 107.3°, whereas the bond angles in phosphine are 93.7°. Which of the following facts correctly identifies the atomic property that makes the two angles different? W) Ammonia and phosphine have different expected VSEPR geometries X) Nitrogen is more electronegative than phosphorus Y) The bonding orbitals of phosphine have more s and less p character than those of ammonia Z) The phosphorus atom is much larger than the nitrogen atom
W: W) Ammonia and phosphine have different expected VSEPR geometries
X: X) Nitrogen is more electronegative than phosphorus
Y: Y) The bonding orbitals of phosphine have more s and less p character than those of ammonia
Z: Z) The phosphorus atom is much larger than the nitrogen atom
Answer: Z) Z) The phosphorus atom is much larger than the nitrogen atom
If $f(x) = x^2 - 1$ and $g(x) = x - 1$, what is the composite function $f(g(x))$?
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Given 2×2 matrices $A = [1\ 3;\ 2\ 1]$ and $B = [3\ 4;\ 1\ 0]$, find the determinant of the product $AB$.
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Which of the following rocks would most likely be created within a fluvial environment? W) Dolostone X) Granite Y) Conglomerate Z) Limestone
W: W) Dolostone
X: X) Granite
Y: Y) Conglomerate
Z: Z) Limestone
Answer: Y) Y) Conglomerate
Which of the following scenarios could strengthen a hurricane? W) It travels over Hispaniola X) It moves into a region with strong upper-level winds Y) It passes over an area of warm surface waters Z) It encounters a polar front
W: W) It travels over Hispaniola
X: X) It moves into a region with strong upper-level winds
Y: Y) It passes over an area of warm surface waters
Z: Z) It encounters a polar front
Answer: Y) Y) It passes over an area of warm surface waters
Which law of physics explains how a changing magnetic field can produce an electric current?
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A wireless router transmits an 802.11a Wi-Fi radio signal at 5 megahertz with a speed up to 54 megabits of data per second. What is the wavelength of the router’s signal in meters? W) 10 X) 15 Y) 60 Z) 150
W: W) 10
X: X) 15
Y: Y) 60
Z: Z) 150
Answer: Y) Y) 60
Which of the following is the least promising method of large-scale oil extraction in the next several decades? W) Drilling access to underground oil reservoirs X) Acquiring oil from whales Y) Acquiring oil from algae Z) Acquiring oil produced by genetically re-engineered Escherichia coli
W: W) Drilling access to underground oil reservoirs
X: X) Acquiring oil from whales
Y: Y) Acquiring oil from algae
Z: Z) Acquiring oil produced by genetically re-engineered Escherichia coli
Answer: X) X) Acquiring oil from whales
Coal combustion products (CCPs) are solid materials produced when coal is burned to generate electricity. Which of the following is NOT a sustainable way to recycle CCPs? W) Adding CCP to biodiesel X) Using CCP as an agricultural fertilizer Y) Adding CCP to concrete Z) Adding CCP to asphalt
W: W) Adding CCP to biodiesel
X: X) Using CCP as an agricultural fertilizer
Y: Y) Adding CCP to concrete
Z: Z) Adding CCP to asphalt
Answer: W) W) Adding CCP to biodiesel
The taxonomic class Myxini contains which of the following fish? W) Wolf eels X) Hagfish Y) Chimaeras Z) Bowfin
W: W) Wolf eels
X: X) Hagfish
Y: Y) Chimaeras
Z: Z) Bowfin
Answer: X) X) Hagfish
In fruit flies, one gene called fruitless is transcribed in both sexes but only translated as a full-length protein in males. A genetic XX female will court other females if she expresses the male form of the fruitless gene. What molecular process must be accurately executed to ensure that the male form is expressed only in males?
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What is the irreducible representation for the atomic orbital s for a molecule with C$_{2v}$ symmetry?
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For 680 mg of tannic acid (molar mass 1700 g/mol) dissolved in water, it takes 40.00 mL of 0.25 M NaOH to titrate the solution to pH 13. Based on this data, how many acidic protons does tannic acid have?
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How many subsets are there of a set whose elements are the composite numbers less than 9?
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A balloon is being filled with water. Its volume in gallons is given by $V(r)=\tfrac{r^3}{10}$, where $r$ is the radius in inches. What is the average rate of change in gallons per inch of the volume as the radius increases from 1 to 2 inches? W) 0.3 X) 0.7 Y) 0.8 Z) 1.2
W: W) 0.3
X: X) 0.7
Y: Y) 0.8
Z: Z) 1.2
Answer: X) X) 0.7
Which of the following minerals has four planes of cleavage? W) Fluorite X) Calcite Y) Augite Z) Muscovite
W: W) Fluorite
X: X) Calcite
Y: Y) Augite
Z: Z) Muscovite
Answer: W) W) Fluorite
What physical law, which ice skaters utilize to increase their rate of spin, is critical in the formation of dust devils, water spouts, and hurricanes?
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A slingshot stretched by a distance $x$ gives a pebble speed $v$. What is the speed of the same pebble if the slingshot is stretched by $2x$ (Hooke’s law)? W) $v/2$ X) $v$ Y) $2v$ Z) $4v$
W: W) $v/2$
X: X) $v$
Y: Y) $2v$
Z: Z) $4v$
Answer: Y) Y) $2v$
Free neutrons decay to protons, electrons, and antineutrinos. What fundamental force is responsible for this decay? W) Weak nuclear X) Strong nuclear Y) Electromagnetic Z) Gravitational
W: W) Weak nuclear
X: X) Strong nuclear
Y: Y) Electromagnetic
Z: Z) Gravitational
Answer: W) W) Weak nuclear
What is the name of the process in which the female gametes are formed in an animal?
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Which of the following terms indicates centromere placement at the end of the chromosome? W) Metacentric X) Acrocentric Y) Telocentric Z) Submetacentric
W: W) Metacentric
X: X) Acrocentric
Y: Y) Telocentric
Z: Z) Submetacentric
Answer: Y) Y) Telocentric
Which of the following statements about ferrimagnetic solids is true? W) Magnetic moments are on different sublattices and are antiparallel X) Magnetic moments are on different sublattices and are parallel Y) Magnetic moments are on the same sublattices and are parallel Z) Magnetic moments are on the same sublattices and are antiparallel
W: W) Magnetic moments are on different sublattices and are antiparallel
X: X) Magnetic moments are on different sublattices and are parallel
Y: Y) Magnetic moments are on the same sublattices and are parallel
Z: Z) Magnetic moments are on the same sublattices and are antiparallel
Answer: W) W) Magnetic moments are on different sublattices and are antiparallel
What is the major product formed at the conclusion of the following two-step reaction sequence: 1) Methylmagnesium bromide, ethylene oxide, and tetrahydrofuran; 2) Ethyl iodide.
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A particle is constrained to move in one dimension according to the relation $x=3t^3$, where $x$ is in meters and $t$ in seconds. What is the acceleration in m/s² at $t=7\,$s? W) 18 X) 126 Y) 441 Z) 1029
W: W) 18
X: X) 126
Y: Y) 441
Z: Z) 1029
Answer: X) X) 126
An RLC circuit consists of a 2 H inductor, a 1000 Ω resistor, an 8 F capacitor, and a power supply in series. With what frequency in hertz must the power supply operate to establish resonance? W) $1/(8\pi)$ X) 1/4 Y) 4 Z) 8π
W: W) $1/(8\pi)$
X: X) 1/4
Y: Y) 4
Z: Z) 8π
Answer: W) W) $1/(8\pi)$
What is the next number in the arithmetic sequence whose first three terms are 17, 31, and 45?
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A card is drawn at random from a standard deck of 52 cards. Given that the card drawn is a face card, what is the probability that the drawn card is a Jack?
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In which of the following locations is it possible to find an esker formed during the Pleistocene epoch? W) Maryland X) West Virginia Y) Tennessee Z) Iowa
W: W) Maryland
X: X) West Virginia
Y: Y) Tennessee
Z: Z) Iowa
Answer: Z) Z) Iowa
Why do tornadoes occur with the lowest frequency near dawn? W) The ground surface is moist, cooling the ground X) The differential between land and air temperatures is at its peak Y) Cloud formation in the early morning hours is rare Z) Air temperature is lowest and radiation deficits are highest
W: W) The ground surface is moist, cooling the ground
X: X) The differential between land and air temperatures is at its peak
Y: Y) Cloud formation in the early morning hours is rare
Z: Z) Air temperature is lowest and radiation deficits are highest
Answer: Z) Z) Air temperature is lowest and radiation deficits are highest
Providing your answer in kJ/mol, what is the average bond energy of the C–H bonds in methane if it takes 1600 kJ to break 1 mol of CH₄ into 1 mol of C and 4 mol of H?
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Organisms are sometimes assigned fractional trophic levels. Which of the following factors is least likely to complicate trophic-level assignment? W) Female black widow spiders cannibalize male black widow spiders after mating X) Bullfrogs eat crayfish while crayfish eat bullfrog tadpoles Y) Bobcats eat rabbits while mountain lions eat both bobcats and rabbits Z) Gorillas eat both bamboo and fruit
W: W) Female black widow spiders cannibalize male black widow spiders after mating
X: X) Bullfrogs eat crayfish while crayfish eat bullfrog tadpoles
Y: Y) Bobcats eat rabbits while mountain lions eat both bobcats and rabbits
Z: Z) Gorillas eat both bamboo and fruit
Answer: Z) Z) Gorillas eat both bamboo and fruit
A 1 kg object is traveling to the left at 3 m/s when it explodes into two equal pieces. One piece travels left at 7 m/s after the explosion. What is the velocity of the other piece? W) 1 m/s to the right X) 1 m/s to the left Y) 4 m/s to the right Z) 4 m/s to the left
W: W) 1 m/s to the right
X: X) 1 m/s to the left
Y: Y) 4 m/s to the right
Z: Z) 4 m/s to the left
Answer: W) W) 1 m/s to the right
What is the root mean square voltage of a power supply that outputs a sinusoidal voltage with a frequency of 60 Hz and a peak voltage of 120 V?
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Bacteria are classified as Gram positive or Gram negative based on several characteristics, including which of the following? W) Genome size X) Cell wall structure Y) Degree of virulence Z) Reproduction rate
W: W) Genome size
X: X) Cell wall structure
Y: Y) Degree of virulence
Z: Z) Reproduction rate
Answer: X) X) Cell wall structure
Which actin-associated motor protein generates the force for muscle contraction?
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Carbon dioxide has a boiling point of –57 °C, whereas sulfur dioxide has a boiling point of –10 °C. This difference is most likely due to the fact that sulfur dioxide exhibits which intermolecular force, while carbon dioxide does not?
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The family of olefin metathesis catalysts developed by Grubbs employs which metallic element?
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A graph has symmetry with respect to the origin and passes through the point (–2, 3). What other point must be on this graph?
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A line in parametric form is given by $x = \tfrac{1}{2}t + 2$ and $y = 2t$. What is the slope of this line?
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Approximately how often is the entire stomach lining in a human replaced? W) Every three days X) Every five days Y) Every week Z) Every month
W: W) Every three days
X: X) Every five days
Y: Y) Every week
Z: Z) Every month
Answer: W) W) Every three days
Polymerase chain reaction (PCR) is a widely used method to rapidly clone pieces of DNA. Place the following three steps of PCR in order for a single amplification cycle: 1) Annealing, 2) Denaturation, 3) Elongation.
Choices:
Correct Order:
Thermohaline circulation in the ocean is controlled most by which of the following? W) Temperature and pressure X) Temperature and salinity Y) Salinity and precipitation Z) Salinity and sea ice formation
W: W) Temperature and pressure
X: X) Temperature and salinity
Y: Y) Salinity and precipitation
Z: Z) Salinity and sea ice formation
Answer: X) X) Temperature and salinity
Why did Charles Keeling’s carbon dioxide graphs show an up-and-down pattern each year? W) More carbon dioxide was generated by heating processes during the winter X) The air is denser in the winter, causing carbon dioxide to become diluted Y) Carbon dioxide is absorbed during the growth season and released through decay during the fall and winter Z) Warmer summer continents release more carbon dioxide than during colder winters
W: W) More carbon dioxide was generated by heating processes during the winter
X: X) The air is denser in the winter, causing carbon dioxide to become diluted
Y: Y) Carbon dioxide is absorbed during the growth season and released through decay during the fall and winter
Z: Z) Warmer summer continents release more carbon dioxide than during colder winters
Answer: Y) Y) Carbon dioxide is absorbed during the growth season and released through decay during the fall and winter
An electron is traveling due north when it experiences a magnetic field that is pointing vertically upward. In what direction will the electron be deflected when it initially encounters the field? W) North X) South Y) East Z) West
W: W) North
X: X) South
Y: Y) East
Z: Z) West
Answer: Z) Z) West
A $3.54\times10^{-10}\,$C charge is placed inside a spherical Gaussian surface of radius 5 m. Given $\varepsilon_0 = 8.85\times10^{-12}\,$F/m, what is the electric flux through this surface in N·m²/C?
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Which type of metabolic pathway uses ATP to build macromolecules, such as proteins, out of smaller components?
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Although coal formed throughout many geological periods, coal from the Lower Triassic period is quite rare. Which of the following is the best possible explanation? W) Terrestrial plants had not yet evolved X) Large animals had not yet evolved Y) A mass extinction occurred Z) Soil density was too low
W: W) Terrestrial plants had not yet evolved
X: X) Large animals had not yet evolved
Y: Y) A mass extinction occurred
Z: Z) Soil density was too low
Answer: Y) Y) A mass extinction occurred
The 2011 Nobel Prize in Physiology or Medicine was awarded to three researchers for their discoveries leading to the characterization of the Toll-like receptor family of molecules. This family plays an important role in which of the following processes? W) Recognizing pathogens in the immune system X) Breaking down lipids in the digestive system Y) Regulating neurotransmitters in the nervous system Z) Enabling meiosis in the reproductive system
W: W) Recognizing pathogens in the immune system
X: X) Breaking down lipids in the digestive system
Y: Y) Regulating neurotransmitters in the nervous system
Z: Z) Enabling meiosis in the reproductive system
Answer: W) W) Recognizing pathogens in the immune system
Assume you would like to isolate a specific membrane protein from a cell. How could you best remove the protein from the membrane? W) Disrupt the lipid bilayer with detergents X) Grind the cells using a pestle Y) Stain the target protein with fluorescing antibodies Z) Centrifuge the cells to separate the lipid bilayer from other cellular components
W: W) Disrupt the lipid bilayer with detergents
X: X) Grind the cells using a pestle
Y: Y) Stain the target protein with fluorescing antibodies
Z: Z) Centrifuge the cells to separate the lipid bilayer from other cellular components
Answer: W) W) Disrupt the lipid bilayer with detergents