NYCNYS Science Resources for Teaching and PD
Science Informational Text
When Whales Walked the Earth (LE)
A newly unearthed fossil is the missing link between land and marine mammals
Standing two to three feet tall on legs adapted to wade through shallow water, the 48-million-year-old Indohyus is the missing link between modern day whales and their land-lubbing ancestors. Hans Thewissen of the Northeastern Ohio Universities Colleges of Medicine and Pharmacy recovered the skeleton in rocks from Kashmir, a disputed region between India and Pakistan, where the deer-like herbivore lived during the Eocene epoch, 56 to 34 million years ago.
The extreme thickness of its bones is a trait seen often in animals that are aquatic waders (thick, heavy bones counteract buoyancy and allow the animal to stay underwater more easily), and chemical traces in its teeth indicate that the animal ate plants in a freshwater environment. Scientists know that Indohyus belongs in the evolutionary path with whales because it has skeletal similarities to both modern whales and known primordial whale ancestors.
Source: Day Greenberg, “When Whales Walked the Earth,” Popular Science, May 2008
Blown Away: Head Lice Meet Hair Dryer of Death (LE)
Head lice are becoming indestructible. A study found that as many as 80 percent of the bugs are [resistant] to insecticides in over-the-counter shampoos, and resistance will only increase. Evolutionary biologist Dale Clayton may have a new line of attack. Clayton, who usually studies lice on bird feathers, stumbled onto his solution after a major research setback. When he moved his laboratory from England to the University of Utah a decade ago, his entire louse collection perished in the dry desert air. Soon after, his 8-year-old came home from school with head lice. He wondered if human head lice could also be killed by drying them out. “It was sort of a forehead slapper,” Clayton says. After conventional hair dryers failed, Clayton came up with the LouseBuster, a 10-pound device resembling a vacuum cleaner that desiccates [dries out] the bugs with a jet of 140-degree air [140°F]. “It’s a pretty brutal assault,” he says. Tests show the invention is both safe and effective, eradicating 80 percent of live lice and 98 percent of eggs, leaving survivors unable to breed. And, Clayton says, “it will be awfully hard for lice to develop resistance.”
Source: Emily Saarman, “Blown Away—Head Lice Meet Hair Dryer of Death,” Discover Magazine, February 2007
(LE) …Corals come in about 1,500 known species—from soft swaying fans to stony varieties with hard skeletons that form reef bases. They are made up of polyps, tiny animals that live in colonies and feed at night on microscopic plants and creatures. The coral’s surface is the living part, with color infused by single-celled algae called zooxanthellae that live in polyp tissue. The algae act like solar panels, passing energy to the coral as they photosynthesize while feeding on the coral’s waste. Extremely sensitive, corals survive in a narrow range of temperature, sunlight and salinity. An uncommonly severe El Niño in 1998 raised ocean temperatures and changed currents, causing bleaching that devastated reefs worldwide. Scientists say parts of the Indian Ocean lost up to 90 percent of corals. The bleaching struck reefs around the Persian Gulf, East Africa, Southeast Asia and the Caribbean. Some recovered. Many died. …
Source: Associated Press, December 2001
The Curious Tale of Asteroid Hermes (ES)
It’s dogma [accepted belief] now: an asteroid hit Earth 65 million years ago and wiped out the dinosaurs. But in 1980 when scientists Walter and Luis Alvarez first suggested the idea to a gathering at the American Association for Advancement of Sciences, their listeners were skeptical. Asteroids hitting Earth? Wiping out species? It seemed incredible.
At that very moment, unknown to the audience, an asteroid named Hermes halfway between Mars and Jupiter was beginning a long plunge toward our planet. Six months later it would pass 300,000 miles from Earth’s orbit, only a little more than the distance to the Moon….
Hermes approaches Earth’s orbit twice every 777 days. Usually our planet is far away when the orbit crossing happens, but in 1937, 1942, 1954, 1974 and 1986, Hermes came harrowingly [dangerously] close to Earth itself. We know about most of these encounters only because Lowell Observatory astronomer Brian Skiff rediscovered Hermes on Oct. 15, 2003. Astronomers around the world have been tracking it carefully ever since.…
Excerpted from “The Curious Tale of Asteroid Hermes,” Dr. Tony Phillips, Science @ NASA, November 3, 2003
Nuclear Waste Storage Plan for Yucca Mountain (ES)
In 1978, the U.S. Department of Energy began a study of Yucca Mountain which is located 90 miles from Las Vegas, Nevada. The study was to determine if Yucca Mountain would be suitable for a long-term burial site for high-level radioactive waste. A three dimensional (3-D) computer scale model of the site was used to simulate the Yucca Mountain area. The computer model study for Yucca Mountain included such variables as: the possibility of earthquakes, predicted water flow through the mountain, increased rainfall due to climate changes, radioactive leakage from the waste containers, and increased temperatures from the buried waste within the containers.
The containers that will be used to store the radioactive waste are designed to last 10,000 years. Within the 10,000-year time period, cesium and strontium, the most powerful radioactive emitters, would have decayed. Other isotopes found in the waste would decay more slowly, but are not powerful radioactive emitters.
In 1998, scientists discovered that the compressed volcanic ash making up Yucca Mountain was full of cracks. Because of the arid climate, scientists assumed that rainwater would move through the cracks at a slow rate. However, when radioactive chlorine-36 was found in rock samples at levels halfway through the mountain, it was clear that rainwater had moved quickly down through Yucca Mountain. It was only 50 years earlier when this chlorine-36 isotope had contaminated rainwater during atmospheric testing of the atom bomb.
Some opponents of the Yucca Mountain plan believe that the uncertainties related to the many variables of the computer model result in limited reliability of its predictions. However, advocates of the plan believe it is safer to replace the numerous existing radioactive burial sites around the United States with the one site at Yucca Mountain. Other opponents of the plan believe that transporting the radioactive waste to Yucca Mountain from the existing 131 burial sites creates too much danger to the United States. In 2002, after years of political debate, a final legislative vote approved the development of Yucca Mountain to replace the existing 131 burial sites.
A Glow in the Dark, and Scientific Peril (Chem)
The [Marie and Pierre] Curies set out to study radioactivity in 1898. Their first accomplishment was to show that radioactivity was a property of atoms themselves. Scientifically, that was the most important of their findings, because it helped other researchers refine their understanding of atomic structure. More famous was their discovery of polonium and radium. Radium was the most radioactive substance the Curies had encountered. Its radioactivity is due to the large size of the atom, which makes the nucleus unstable and prone to decay, usually to radon and then lead, by emitting particles and energy as it seeks a more stable configuration. Marie Curie struggled to purify radium for medical uses, including early radiation treatment for tumors. But radium’s bluish glow caught people’s fancy, and companies in the
United States began mining it and selling it as a novelty: for glow-in-the-dark light pulls, for instance, and bogus cure-all patent medicines that actually killed people. What makes radium so dangerous is that it forms chemical bonds in the same way as calcium, and the body can mistake it for calcium and absorb it into the bones. Then, it can bombard cells with radiation at close range, which may cause bone tumors or bone-marrow damage that can give rise to anemia or leukemia.
— Denise Grady, The New York Times, October 6, 1998
--- Chemistry
In 1897, J. J. Thomson demonstrated in an experiment that cathode rays were deflected by an electric field. This suggested that cathode rays were composed of negatively charged particles found in all atoms. Thomson concluded that the atom was a positively charged sphere of almost uniform density in which negatively charged particles were embedded. The total negative charge in the atom was balanced by the positive charge, making the atom electrically neutral. In the early 1900s, Ernest Rutherford bombarded a very thin sheet of gold foil with alpha particles. After interpreting the results of the gold foil experiment, Rutherford proposed a more sophisticated model of the atom.
---Chemistry
A fluorescent light tube contains a noble gas and a drop of mercury. When the fluorescent light operates, the Hg is a vapor and there are free-flowing Hg ions and electrons in the tube. The electrons collide with Hg atoms that then emit ultraviolet (UV) radiation. The inside of the tube is coated with a mixture of several compounds that absorbs UV radiation. Ions in the coating emit a blend of red, green, and blue light that together appears as white light. The compound that produces red light is Y2O3. The compound that produces green light is CeMgAl11O19. The compound that produces blue light is BaMgAl10O17.
---Chemistry
Graphite and diamond are two crystalline arrangements for carbon. The crystal structure of graphite is organized in layers. The bonds between carbon atoms within each layer of graphite are strong. The bonds between carbon atoms that connect different layers of graphite are weak because the shared electrons in these bonds are loosely held by the carbon atoms. The crystal structure of diamond is a strong network of atoms in which all the shared electrons are strongly held by the carbon atoms. Graphite is an electrical conductor, but diamond is not. At 25°C, graphite has a density of 2.2 g/cm3 and diamond has a density of 3.51 g/cm3. The element oxygen can exist as diatomic molecules, O2, and as ozone, O3. At standard pressure the boiling point of ozone is 161 K.
A New Oregon Volcano?
The Three Sisters are 10,000-foot volcanic mountain peaks in Oregon. Volcanic eruptions began building the Three Sisters from andesitic lava and cinders 700,000 years ago. The last major eruption occurred 2000 years ago.
West of the Three Sisters peaks, geologists have recently discovered that Earth’s surface is bulging upward in a bull’s-eye pattern 10 miles wide. There is a 4-inch rise at its center, which geologists believe could be the beginning of another volcano. The uplift was found by comparing satellite images. This uplift in Oregon may allow the tracking of a volcanic eruption from its beginning, long before the smoke and explosions begin. This uplift is most likely caused by an upflow of molten rock from more than four miles below the surface. Rock melts within Earth’s interior and then moves upward in cracks in Earth’s crust, where it forms large underground pools called magma chambers. Magma upwelling often produces signs that help scientists predict eruptions and protect humans. When the pressure of rising magma becomes forceful enough to crack bedrock, swarms of small earthquakes occur. Rising magma releases carbon dioxide and other gases that can be detected at the surface.
The Pine Bush Region (ES)
The Pine Bush region, just northwest of Albany, New York, is a 40-square mile area of sand dunes and wetlands covered by pitch pine trees and scrub oak bushes. During the Ordovician Period, this area was covered by a large sea. Layers of mud and sand deposited in this sea were compressed into shale and sandstone bedrock.
During most of the Cenozoic Era, running water eroded stream channels into the bedrock. One of these buried channels is shown at location A in the cross section. Over the last one million years of the Cenozoic Era, this area was affected by glaciation. During the last major advance of glacial ice, soil and bedrock were eroded and later deposited as till (a mixture of boulders, pebbles, sand, and clay). About 20,000 years ago, the last glacier in New York State began to melt. The meltwater deposited pebbles and sand, forming the stratified drift. During the 5000 years it took to melt this glacier, the entire Pine Bush area became submerged under a large 350-foot-deep glacial lake called Lake Albany. Delta deposits of cobbles, pebbles, and sand formed along the lake shorelines, and beds of silt and clay were deposited farther into the lake. Lake Albany drained about 12,000 years ago, exposing the lake bottom. Wind erosion created the sand dunes that cover much of the Pine Bush area today.
Ozone in Earth’s Atmosphere (ES)
Ozone is a special form of oxygen. Unlike the oxygen we breathe, which is composed of two atoms of oxygen, ozone is composed of three atoms of oxygen. A concentrated ozone layer between 10 and 30 miles above Earth’s surface absorbs some of the harmful ultraviolet radiation coming from the Sun. The amount of ultraviolet light reaching
Earth’s surface is directly related to the angle of incoming solar radiation. The greater the Sun’s angle of insolation, the greater the amount of ultraviolet light that reaches Earth’s surface. If the ozone layer were completely destroyed, the ultraviolet light reaching Earth’s surface would most likely increase human health problems, such as skin cancer and eye damage.
More Sci- Than Fi, Physicists Create Antimatter (Physics)
Physicists working in Europe announced yesterday that they had passed through nature’s looking glass and had created atoms made of antimatter, or antiatoms, opening up the possibility of experiments in a realm once reserved for science fiction writers. Such experiments, theorists say, could test some of the basic tenets of modern physics and light the way to a deeper understanding of nature. By corralling [holding together in groups] clouds of antimatter particles in a cylindrical chamber laced with detectors and electric and magnetic fields, the physicists assembled antihydrogen atoms, the looking glass equivalent of hydrogen, the most simple atom in nature. Whereas hydrogen consists of a positively charged proton circled by a negatively charged electron, in antihydrogen the proton’s counterpart, a positively charged antiproton, is circled by an antielectron, otherwise known as a positron.
According to the standard theories of physics, the antimatter universe should look identical to our own. Antihydrogen and hydrogen atoms should have the same properties, emitting the exact same frequencies of light, for example. . . .
Antimatter has been part of physics since 1927 when its existence was predicted by the British physicist Paul Dirac. The antielectron, or positron, was discovered in 1932. According to the theory, matter can only be created in particle antiparticle pairs. It is still a mystery, cosmologists say, why the universe seems to be overwhelmingly composed of normal matter.
Dennis Overbye, “More Sci- Than Fi, Physicists Create Antimatter,” New York Times, Sept. 19, 2002
Chemistry
Polonium-210 occurs naturally, but is scarce. Polonium-210 is primarily used in devices
designed to eliminate static electricity in machinery. It is also used in brushes to remove
dust from camera lenses.
Polonium-210 can be created in the laboratory by bombarding bismuth-209 with
neutrons to create bismuth-210. The bismuth-210 undergoes beta decay to produce
polonium-210. Polonium-210 has a half-life of 138 days and undergoes alpha decay.
83 State one beneficial use of Po-210. [1]
84 Complete the nuclear equation in your answer booklet for the decay of Po-210, by writing a notation for the missing product. [1]
85 Determine the total mass of an original 28.0-milligram sample of Po-210 that remains unchanged after 414 days. [1]
************
The catalytic converter in an automobile changes harmful gases produced during fuel
combustion to less harmful exhaust gases. In the catalytic converter, nitrogen dioxide reacts
with carbon monoxide to produce nitrogen and carbon dioxide. In addition, some carbon
monoxide reacts with oxygen, producing carbon dioxide in the converter. These reactions
are represented by the balanced equations below.
Reaction 1: 2NO2(g) + 4CO(g) →N2(g) + 4CO2(g) + 1198.4 kJ
Reaction 2: 2CO(g) + O2(g) →2CO2(g) + 566.0 kJ
73 The potential energy diagram in your answer booklet represents reaction 1 without a catalyst. On the same diagram, draw a dashed line to indicate how potential energy changes when the reaction is catalyzed in the converter. [1]
74 Determine the oxidation number of carbon in each carbon compound in reaction 2. Your response must include both the sign and value of each oxidation number. [1]
**********
Two sources of copper are cuprite, which has the IUPAC name copper(I) oxide, and
malachite, which has the formula Cu2CO3(OH)2. Copper is used in home wiring and
electric motors because it has good electrical conductivity. Other uses of copper not
related to its electrical conductivity include coins, plumbing, roofing, and cooking pans.
Aluminum is also used for cooking pans.
At room temperature, the electrical conductivity of a copper wire is 1.6 times greater
than an aluminum wire with the same length and cross-sectional area. At room temperature,
the heat conductivity of copper is 1.8 times greater than the heat conductivity of aluminum.
At STP, the density of copper is 3.3 times greater than the density of aluminum.
80 Write the chemical formula of cuprite. [1]
81 Determine the oxidation number of oxygen in the carbonate ion found in malachite. [1]
82 Identify one physical property of copper that makes it a good choice for uses that are not related to electrical conductivity. [1]
83 Identify one physical property of aluminum that could make it a better choice than copper for a cooking pan. [1]
**********
In 1897, J. J. Thomson demonstrated in an experiment that cathode rays were deflected
by an electric field. This suggested that cathode rays were composed of negatively charged
particles found in all atoms. Thomson concluded that the atom was a positively charged
sphere of almost uniform density in which negatively charged particles were embedded.
The total negative charge in the atom was balanced by the positive charge, making the atom
electrically neutral.
In the early 1900s, Ernest Rutherford bombarded a very thin sheet of gold foil with
alpha particles. After interpreting the results of the gold foil experiment, Rutherford
proposed a more sophisticated model of the atom.
66 State one conclusion from Rutherford’s experiment that contradicts one conclusion
made by Thomson. [1]
67 State one aspect of the modern model of the atom that agrees with a conclusion made
by Thomson. [1]
A fluorescent light tube contains a noble gas and a drop of mercury. When the
fluorescent light operates, the Hg is a vapor and there are free-flowing Hg ions and
electrons in the tube. The electrons collide with Hg atoms that then emit ultraviolet (UV)
radiation.
The inside of the tube is coated with a mixture of several compounds that absorbs
UV radiation. Ions in the coating emit a blend of red, green, and blue light that together
appears as white light. The compound that produces red light is Y2O3. The compound that
produces green light is CeMgAl11O19. The compound that produces blue light is
BaMgAl10O17.
75 Write the chemical name of the compound that produces red light. [1]
76 Calculate the percent composition by mass of aluminum in the compound that produces green light. Your response must include both a correct numerical setup and the calculated result. [2]
77 Explain, in terms of both electrons and energy, how ions in the coating emit light. [1]
Carbon and oxygen are examples of elements that exist in more than one form in the same phase.
Graphite and diamond are two crystalline arrangements for carbon. The crystal
structure of graphite is organized in layers. The bonds between carbon atoms within each
layer of graphite are strong. The bonds between carbon atoms that connect different
layers of graphite are weak because the shared electrons in these bonds are loosely held by
the carbon atoms. The crystal structure of diamond is a strong network of atoms in which
all the shared electrons are strongly held by the carbon atoms. Graphite is an electrical
conductor, but diamond is not. At 25°C, graphite has a density of 2.2 g/cm3 and diamond
has a density of 3.51 g/cm3.
The element oxygen can exist as diatomic molecules, O2, and as ozone, O3. At standard
pressure the boiling point of ozone is 161 K.
70 Explain, in terms of electrons, why graphite is an electrical conductor and diamond is not. Your response must include information about both graphite and diamond. [1]
71 Calculate the volume, in cm3, of a diamond at 25°C that has a mass of 0.200 gram. Your response must include both a correct numerical setup and the calculated result. [2]
72 Explain, in terms of intermolecular forces, the difference in the boiling points of O2 and O3 at standard pressure. Your response must include information about both O2 and O3. [1]
The health of fish depends on the amount of oxygen dissolved in the water. A dissolved
oxygen (DO) concentration between 6 parts per million and 8 parts per million is best for
fish health. A DO concentration greater than 1 part per million is necessary for fish survival.
Fish health is also affected by water temperature and concentrations of dissolved
ammonia, hydrogen sulfide, chloride compounds, and nitrate compounds. Most freshwater
fish thrive in water with a pH between 6.5 and 8.5.
A student’s fish tank contains fish, green plants, and 3800 grams of fish-tank water with
2.7 ⋅ 10–2 gram of dissolved oxygen. Phenolphthalein tests colorless and bromthymol blue
tests blue in samples of the fish-tank water.
68 Based on the test results for the indicators phenolphthalein and bromthymol blue, what
is the pH range of the fish-tank water? [1]
69 When the fish-tank water has a pH of 8.0, the hydronium ion concentration is
1.0 ⋅ 10–8 mole per liter. What is the hydronium ion concentration when the water has
a pH of 7.0? [1]
70 State how an increase in the temperature of the fish-tank water affects the solubility of
oxygen in the water. [1]
71 Determine if the DO concentration in the fish tank is healthy for fish. Your response
must include:
• a correct numerical setup to calculate the DO concentration in the water in parts per
million [1]
• the calculated result [1]
• a statement using your calculated result that tells why the DO concentration in the
water is or is not healthy for fish [1]
A New Oregon Volcano?
The Three Sisters are 10,000-foot volcanic mountain peaks in Oregon. Volcanic
eruptions began building the Three Sisters from andesitic lava and cinders 700,000 years
ago. The last major eruption occurred 2000 years ago.
West of the Three Sisters peaks, geologists have recently discovered that Earth’s surface
is bulging upward in a bull’s-eye pattern 10 miles wide. There is a 4-inch rise at its center,
which geologists believe could be the beginning of another volcano. The uplift was found
by comparing satellite images. This uplift in Oregon may allow the tracking of a volcanic
eruption from its beginning, long before the smoke and explosions begin.
This uplift is most likely caused by an upflow of molten rock from more than four miles
below the surface. Rock melts within Earth’s interior and then moves upward in cracks in
Earth’s crust, where it forms large underground pools called magma chambers. Magma
upwelling often produces signs that help scientists predict eruptions and protect humans.
When the pressure of rising magma becomes forceful enough to crack bedrock, swarms of
small earthquakes occur. Rising magma releases carbon dioxide and other gases that can be
detected at the surface.
81 Identify one of the minerals found in the andesite rock of the Three Sisters
volcanoes. [1]
82 The cross section in your answer booklet represents Earth’s interior beneath the
Three Sisters. Place a triangle, _, on the cross section to indicate the location where
the new volcano will most likely form. [1]
83 On the same cross section, place arrows through each point, X, Y, and Z, to indicate
the relative motion of each of these sections of the lithosphere. [1]
Ozone in Earth’s Atmosphere
Ozone is a special form of oxygen. Unlike the oxygen we breathe, which is composed
of two atoms of oxygen, ozone is composed of three atoms of oxygen. A concentrated
ozone layer between 10 and 30 miles above Earth’s surface absorbs some of the harmful
ultraviolet radiation coming from the Sun. The amount of ultraviolet light reaching
Earth’s surface is directly related to the angle of incoming solar radiation. The greater the
Sun’s angle of insolation, the greater the amount of ultraviolet light that reaches Earth’s
surface. If the ozone layer were completely destroyed, the ultraviolet light reaching
Earth’s surface would most likely increase human health problems, such as skin cancer
and eye damage.
80 State the name of the temperature zone of Earth’s atmosphere where the
concentrated layer of ozone gas exists. [1]
81 Explain how the concentrated ozone layer above Earth’s surface is beneficial to
humans. [1]
82 Assuming clear atmospheric conditions, on what day of the year do people in New
York State most likely receive the most ultraviolet radiation from the Sun? [1]
The Gakkel Ridge
In the summer of 2001, scientists aboard the U.S. Coast Guard icebreaker
Healy visited one of the least explored places on Earth. The scientists studied the
1800-kilometer-long Gakkel Ridge at the bottom of the Arctic Ocean near the
North Pole. The Gakkel Ridge is a section of the Arctic Mid-Ocean Ridge and
extends from the northern end of Greenland across the Arctic Ocean floor toward
Russia. At a depth of about 5 kilometers below the ocean surface, the Gakkel
Ridge is one of the deepest mid-ocean ridges in the world. The ridge is believed
to extend down to Earth’s mantle, and the new seafloor being formed at the ridge
is most likely composed of huge slabs of mantle rock. Bedrock samples taken from
the seafloor at the ridge were determined to be the igneous rock peridotite.
The Gakkel Ridge is also the slowest moving mid-ocean ridge. Some ridge
systems, like the East Pacific Ridge, are rifting at a rate of about 20 centimeters
per year. The Gakkel Ridge is rifting at an average rate of less than 1 centimeter
per year. This slow rate of movement means that there is less volcanic activity
along the Gakkel Ridge than along other ridge systems. However, heat from the
underground magma slowly seeps up through cracks in the rocks of the ridge at
structures scientists call hydrothermal (hot water) vents. During the 2001 cruise,
a major hydrothermal vent was discovered at 87° N latitude 45° E longitude.
77 On the map in your answer booklet, place an X on the location of the major hydrothermal
vent described in the passage. [1]
78 Describe the relative motion of the two tectonic plates on either side of the Gakkel
Ridge. [1]
79 The Gakkel Ridge is a boundary between which two tectonic plates? [1]
80 Identify one feature, other than hydrothermal vents, often found at mid-ocean ridges
like the Gakkel Ridge that indicates heat from Earth’s interior is escaping. [1]
81 State the two minerals that were most likely found in the igneous bedrock samples
collected at the Gakkel Ridge. [1]
The Pine Bush Region
The Pine Bush region, just northwest of Albany, New York, is a 40-square mile area
of sand dunes and wetlands covered by pitch pine trees and scrub oak bushes. During
the Ordovician Period, this area was covered by a large sea. Layers of mud and sand
deposited in this sea were compressed into shale and sandstone bedrock.
During most of the Cenozoic Era, running water eroded stream channels into the
bedrock. One of these buried channels is shown at location A in the cross section. Over
the last one million years of the Cenozoic Era, this area was affected by glaciation.
During the last major advance of glacial ice, soil and bedrock were eroded and later
deposited as till (a mixture of boulders, pebbles, sand, and clay).
About 20,000 years ago, the last glacier in New York State began to melt. The
meltwater deposited pebbles and sand, forming the stratified drift. During the 5000
years it took to melt this glacier, the entire Pine Bush area became submerged under
a large 350-foot-deep glacial lake called Lake Albany. Delta deposits of cobbles,
pebbles, and sand formed along the lake shorelines, and beds of silt and clay were
deposited farther into the lake.
Lake Albany drained about 12,000 years ago, exposing the lake bottom. Wind
erosion created the sand dunes that cover much of the Pine Bush area today.
70 According to the passage, how old is the bedrock shown in the cross section? [1]
71 What evidence shown at location A suggests that the channel in the bedrock was
eroded by running water? [1]
72 List, from oldest to youngest, the four types of sediment shown above the bedrock in
the cross section. [1]
73 Explain why the till layer is composed of unsorted sediment. [1]
74 How does the shape of the sand dune at location B provide evidence that the
prevailing winds that formed this dune were blowing from the southwest? [1]
Precious Gemstones
Some precious gemstones are a form of the mineral corundum, which has a hardness
of 9. Corundum is a rare mineral made up of closely packed aluminum and
oxygen atoms, and its formula is Al2O3. If small amounts of chromium replace some
of the aluminum atoms in corundum, a bright-red gemstone called a ruby is produced.
If traces of titanium and iron replace some aluminum atoms, deep-blue sapphires can
be produced.
Most of the world’s ruby deposits are found in metamorphic rock that is located
along the southern slope of the Himalayas, where plate tectonics played a part in ruby
formation. Around 50 million years ago, the Tethys Sea was located between what is
now India and Eurasia. Much of the Tethys Sea bottom was composed of limestone
that contained the elements needed to make these precious gemstones. The Tethys
Sea closed up as the Indian-Australian Plate pushed under the Eurasian Plate, creating
the Himalayan Mountains. The limestone rock lining the seafloor underwent
metamorphism as it was pushed deep into Earth by the Indian-Australian Plate. For
the next 40 to 45 million years, as the Himalayas rose, rubies, sapphires, and other
gemstones continued to form.
Is Earth Gaining Weight?
Scientists believe that Earth may gain more than 100 tons of dust from space every
day. The dust comes from thawing comets as they orbit the Sun and from pieces of
asteroids that collided with other asteroids. Most asteroids orbit the Sun between Mars
and Jupiter. Each dust particle dates back to the days when our solar system was
created. So in a way, each tiny speck of dust holds clues to how our solar system
formed.
All the space dust produced by comets and asteroids in our solar system is drawn
to the Sun by its gravitational force. However, space dust that passes within about
60 miles of Earth’s surface may be slowed enough by friction with Earth’s atmosphere
to be pulled to the surface by Earth’s gravity.
51 State one reason why more space dust is attracted to the Sun than to Earth. [1]
52 In which temperature zone of Earth’s atmosphere is space dust first slowed enough
by friction to be pulled to Earth’s surface? [1]
53 Approximately how many million kilometers from the Sun are most asteroids
located? [1]
Asbestos
Asbestos is a general name given to the fibrous varieties of six naturally occurring
minerals used in commercial products. Most asbestos minerals are no longer mined
due to the discovery during the 1970s that long-term exposure to high concentrations
of their long, stiff fibers leads to health problems. Workers who produce or handle
asbestos products are most at risk, since inhaling high concentrations of airborne fibers
allows the asbestos particles to become trapped in the workers’ lungs. Chrysotile is a
variety of asbestos that is still mined because it has short, soft, flexible fibers that do
not pose the same health threat.
82 State one reason for the decline in global asbestos use after 1980. [1]
83 Chrysotile is found with other minerals in New York State mines located near
44° 30' N, 74° W. In which New York State landscape region are these mines
located? [1]
84 What determines the physical properties of minerals, such as the long, stiff fibers of
some varieties of asbestos? [1]
85 The chemical formula for chrysotile is Mg3Si2O5(OH)4. State the name of the
mineral found on the Earth Science Reference Tables that is most similar in chemical
composition. [1]
Earth’s Early Atmosphere
Early in Earth’s history, the molten outer layers of Earth released gases to form an
early atmosphere. Cooling and solidification of that molten surface formed the early
lithosphere approximately 4.4 billion years ago. Around 3.3 billion years ago,
photosynthetic organisms appeared on Earth and removed large amounts of carbon
dioxide from the atmosphere, which allowed Earth to cool even faster. In addition,
they introduced oxygen into Earth’s atmosphere, as a by-product of photosynthesis.
Much of the first oxygen that was produced reacted with natural Earth elements, such
as iron, in the lithosphere and produced new varieties of rocks and minerals.
Eventually, photosynthetic organisms produced enough oxygen so that it began to
accumulate in Earth’s atmosphere. About 450 million years ago, there was enough
oxygen in the atmosphere to allow for the development of an ozone layer 30 to 50
kilometers above Earth’s surface. This layer was thick enough to protect organisms
developing on land from the ultraviolet radiation from the Sun.
51 State one reason why the first rocks on Earth were most likely igneous in origin. [1]
52 Identify one mineral with a red-brown streak that formed when oxygen in Earth’s
early atmosphere combined with iron. [1]
53 Identify the temperature zone of the atmosphere in which the ozone layer developed. [1]
54 Complete the pie graph in your answer booklet to show the percent by volume of
nitrogen and oxygen gases currently found in Earth’s troposphere. Label each
section of the graph with the name of the gas. The percentage of other gases is
shown. [1]
Nuclear Waste Storage Plan for Yucca Mountain
In 1978, the U.S. Department of Energy began a study of Yucca Mountain which is
located 90 miles from Las Vegas, Nevada. The study was to determine if Yucca Mountain
would be suitable for a long-term burial site for high-level radioactive waste. A threedimensional
(3-D) computer scale model of the site was used to simulate the Yucca
Mountain area. The computer model study for Yucca Mountain included such variables as:
the possibility of earthquakes, predicted water flow through the mountain, increased rainfall
due to climate changes, radioactive leakage from the waste containers, and increased
temperatures from the buried waste within the containers.
The containers that will be used to store the radioactive waste are designed to last 10,000
years. Within the 10,000-year time period, cesium and strontium, the most powerful
radioactive emitters, would have decayed. Other isotopes found in the waste would decay
more slowly, but are not powerful radioactive emitters.
In 1998, scientists discovered that the compressed volcanic ash making up Yucca Mountain
was full of cracks. Because of the arid climate, scientists assumed that rainwater would move
through the cracks at a slow rate. However, when radioactive chlorine-36 was found in rock
samples at levels halfway through the mountain, it was clear that rainwater had moved
quickly down through Yucca Mountain. It was only 50 years earlier when this chlorine-36
isotope had contaminated rainwater during atmospheric testing of the atom bomb.
Some opponents of the Yucca Mountain plan believe that the uncertainties related to the
many variables of the computer model result in limited reliability of its predictions.
However, advocates of the plan believe it is safer to replace the numerous existing radioactive
burial sites around the United States with the one site at Yucca Mountain. Other
opponents of the plan believe that transporting the radioactive waste to Yucca Mountain
from the existing 131 burial sites creates too much danger to the United States. In 2002,
after years of political debate, a final legislative vote approved the development of Yucca
Mountain to replace the existing 131 burial sites.
68 State one uncertainty in the computer model that limits the reliability of this
computer model. [1]
69 Scientists assume that a manufacturing defect would cause at least one of the waste
containers stored in the Yucca Mountain repository to leak within the first 1,000 years.
State one possible effect such a leak could have on the environment near Yucca
Mountain. [1]
70 State one risk associated with leaving radioactive waste in the 131 sites around the
country where it is presently stored. [1]
71 If a sample of cesium-137 is stored in a waste container in Yucca Mountain, how much
time must elapse until only of the original sample remains unchanged? [1]
72 The information states “Within the 10,000-year time period, cesium and strontium, the
most powerful radioactive emitters, would have decayed.” Use information from
Reference Table N to support this statement. [1]
73 Why is water flow a crucial factor in deciding whether Yucca Mountain is a suitable
burial site? [1]
1
32
P.
For years, theoretical physicists have been refining a mathematical method called
lattice quantum chromodynamics to enable them to predict the masses of particles consisting
of various combinations of quarks and antiquarks. They recently used the theory to
calculate the mass of the rare Bc particle, consisting of a charm quark and a bottom antiquark.
The predicted mass of the Bc particle was about six times the mass of a proton.
Shortly after the prediction was made, physicists working at the Fermi National
Accelerator Laboratory, Fermilab, were able to measure the mass of the Bc particle experimentally
and found it to agree with the theoretical prediction to within a few tenths of a
percent. In the experiment, the physicists sent beams of protons and antiprotons moving at
99.999% the speed of light in opposite directions around a ring 1.0 kilometer in radius. The
protons and antiprotons were kept in their circular paths by powerful electromagnets.
When the protons and antiprotons collided, their energy produced numerous new particles,
including the elusive Bc.
These results indicate that lattice quantum chromodynamics is a powerful tool not only
for confirming the masses of existing particles, but also for predicting the masses of particles
that have yet to be discovered in the laboratory.
70 Identify the class of matter to which the Bc particle belongs. [1]
71 Determine both the sign and the magnitude of the charge of the Bc particle in elementary charges. [1]
72 Explain how it is possible for a colliding proton and antiproton to produce a particle with six times the mass
of either. [1]
Physics–
More Sci- Than Fi, Physicists Create Antimatter
Physicists working in Europe announced yesterday that they had passed
through nature’s looking glass and had created atoms made of antimatter, or
antiatoms, opening up the possibility of experiments in a realm once reserved for
science fiction writers. Such experiments, theorists say, could test some of the basic
tenets of modern physics and light the way to a deeper understanding of nature.
By corralling [holding together in groups] clouds of antimatter particles in a
cylindrical chamber laced with detectors and electric and magnetic fields, the
physicists assembled antihydrogen atoms, the looking glass equivalent of hydrogen,
the most simple atom in nature. Whereas hydrogen consists of a positively charged
proton circled by a negatively charged electron, in antihydrogen the proton’s
counterpart, a positively charged antiproton, is circled by an antielectron, otherwise
known as a positron.
According to the standard theories of physics, the antimatter universe should
look identical to our own. Antihydrogen and hydrogen atoms should have the same
properties, emitting the exact same frequencies of light, for example. . . .
Antimatter has been part of physics since 1927 when its existence was
predicted by the British physicist Paul Dirac. The antielectron, or positron, was
discovered in 1932. According to the theory, matter can only be created in particleantiparticle
pairs. It is still a mystery, cosmologists say, why the universe seems to be
overwhelmingly composed of normal matter.
Dennis Overbye, “More Sci- Than Fi, Physicists
Create Antimatter,” New York Times, Sept. 19, 2002
74 The author of the passage concerning antimatter incorrectly reported the findings of
the experiment on antimatter. Which particle mentioned in the article has the
charge incorrectly identified? [1]
75 How should the emission spectrum of antihydrogen compare to the emission spectrum
of hydrogen? [1]
76 Identify one characteristic that antimatter particles must possess if clouds of them
can be corralled by electric and magnetic fields. [1]
77 According to the article, why is it a mystery that “the universe seems to be overwhelmingly
composed of normal matter”? [1]
Mayflies
Mayflies belong to a group of insects known as Ephemeroptera, which means “shortlived
wings.” They have been given this name because the adult, the only stage that has
wings, lives for only a few days.
The aquatic juvenile form of most mayfly species lives for several years under rocks in
streams that have high levels of dissolved oxygen. The juveniles feed on microscopic
photosynthetic organisms. Juveniles supply food for trout and other stream fish.
Millions of adult mayflies emerge from stream water in early summer. The adults have
wings for flight, but lack functional mouth parts. Their energy supply comes from food
stored in their bodies. Birds and bats eat adult mayflies. Adult mayflies mate, lay eggs, and
die within a few days.
Dandelions are weeds that are very common in many grassy areas of New York State.
Dandelion flowers first open up in a bright-yellow stage, and later turn a fluffy white when
they are ready to release their seeds. The seeds are carried by the wind, and can sometimes
travel great distances before landing and growing into new plants. The stems of dandelions
are usually very long, typically about 20–30 centimeters (cm), and stand high above the
surrounding grass.
A science teacher in Niagara County discovered an area in her lawn where nearly every
dandelion had a stem less than 1 cm long. These short dandelions were replacing large
amounts of grass in the lawn surrounding her house. They were growing much more
thickly than the taller dandelions in other nearby areas. The short dandelions appeared to
be growing very successfully in one area of her lawn, but did not appear to have spread to
other areas of her lawn. The science teacher noticed that every time she mowed her lawn,
the short dandelions were left untouched by the mower blades, and that their numbers
were steadily increasing.
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