Earth Science - California Standards Tests (CSTs) Released Items

A teacher demonstrated the possible effects of acid rain by placing several types of rocks in separate beakers containing a vinegar solution with a pH of 3. As time passed, some of the solutions retained a pH of 3 while other solutions gradually reached a pH of 7. Which of the following best explains this variation of pH in this demonstration?
1. All solutions eventually reach a pH of 7, so the experiment is not complete.
2. Vinegar is an organic compound that reacts unpredictably with inorganic rocks.
3. The rocks have varying chemical composition, so some but not all of them react with acid.
4. The students should have measured the pH immediately after mixing since acid rain reacts quickly in nature.
A day on Saturn takes about 10 Earth hours. Which fact would best explain this short day?
1. Saturn is less dense than Earth.
2. Saturn is much farther from the Sun than Earth.
3. Saturn rotates more rapidly than Earth.
4. Saturn’s orbit has greater eccentricity than Earth’s.
The highest elevation on this topographic map can be no more than about
1. 25 meters.
2. 34 meters.
3. 45 meters.
4. 49 meters.
In an area where a river has cut deep into Earth, there are several layers of very different rock exposed. The oldest rock layer is most likely to be the layer that is
1. below the other layers.
2. the thickest layer.
3. the most rich in fossils.
4. igneous intrusive rock.
A student models an impact crater on the Moon by dropping a marble from a known height onto a pan of smooth flour. Before reaching any conclusions about the results of this simple experiment, the student repeats the activity several times so that
1. differences produced by standard variability in conditions become clear.
2. she can produce as large a crater as possible before measuring a diameter.
3. her ability to simulate a meteor impact becomes more realistic with practice.
4. she can illustrate a perfectly circular crater for her write-up of the experiment.
The existence of extraterrestrial life may never be proven, but this idea will become more scientifically acceptable over time if
1. no one disputes this idea in a scientific forum.
2. hypotheses are made related to the idea.
3. alternative hypotheses are proposed and confirmed.
4. increasing scientific evidence supports the idea.
An astronomer notes the change in position of Mars over several nights and then calculates that Mars orbits the Sun once every 400 Earth days. This figure is considerably lower than the 687 Earth-day orbit that is widely accepted for Mars. The scientist should
1. publish the findings to reveal the flaw in established orbital theories.
2. form a hypothesis to explain how the orbit of Mars can vary so greatly.
3. gather a new set of data and see if the results remain the same.
4. add 287 days to the calculations to match the accepted figure.
Which of the following statements best describes how the planets of the solar system formed?
1. They are condensed rings of matter thrown off by the young Sun.
2. They are the remains of an exploded star once paired with the Sun.
3. The Sun captured them from smaller, older nearby stars.
4. They formed from a nebular cloud of dust and gas.
Which planet was formed from the light gases of the outer solar nebula?
1. Mars
2. Mercury
3. Venus
4. Uranus
The diameter of Saturn is almost ten times that of the Earth, yet its density is much less. This can best be explained by the fact that Saturn
1. is farther from the Sun.
2. is a gaseous planet.
3. has a shorter period of rotation.
4. has a ring around its center.
Evidence suggests that Earth is about 4.6 billion years old, even though no Earth rocks have been found that can be dated at more than 4 billion years old. This discrepancy is most likely caused by Earth’s original crust being
1. difficult to date so precisely.
2. subject to extensive erosion.
3. blasted away during Earth’s formation.
4. destroyed by solar radiation.
It has been determined that the oldest rocks retrieved from the Moon by Apollo astronauts were formed 4.44 billion years ago, while the oldest rocks found on Earth are less than 4 billion years old. This difference is most likely because
1. Earth formed well after the Moon was formed.
2. Earth cooled more slowly than the Moon.
3. Earth’s oldest rocks have been recycled by plate tectonics and erosion.
4. Earth and the Moon were both captured by the Sun’s gravity at different times.
Before humans visited the Moon and brought back lunar rocks, the age of the Moon was unknown. Radioisotope dating of these rocks showed that the age of the oldest lunar rock was closest to
1. 186,000 years.
2. 6.5 million years.
3. 4.4 billion years.
4. 15 billion years.
Which of the following is the best evidence that Earth’s continents were once in vastly different positions than they are today?
1. Penguins are found only in the Southern Hemisphere.
2. Fossils of tropical plants are found in Antarctica.
3. Volcanoes encircle the Pacific Ocean.
4. Major rivers form deltas from continental erosion.
Early telescopes showed stars as only points of light, while the planets appeared to be much larger, providing evidence that stars must
1. be more plentiful in our solar system than planets.
2. travel in elliptical orbits like planets.
3. be much farther from Earth than planets.
4. reflect much more light than planets.
Although many ancient civilizations designated certain patterns of stars as constellations, they never included planets in their constellations. What feature of planets, as opposed to stars, explains this?
1. They look bigger than stars.
2. They are more difficult to see than stars.
3. There are not enough of them to form a constellation.
4. They do not maintain fixed positions relative to other planets or stars.
Before the telescope was invented, people had the idea that the planets were closer to Earth than were the stars. Which piece of evidence contributed to this conclusion?
1. The planets were the only objects with visible moons.
2. The Milky Way was sometimes visible during the day.
3. The stars were consistently brighter than the planets.
4. The planets appeared to move much more quickly than the stars.
What is the source of energy for the Sun?
1. hydrogen fusion
2. internal combustion
3. nuclear fission of metals
4. burning of solar gases
Fusion is a form of nuclear reaction resulting in an enormous release of heat energy. The fusion of hydrogen to helium is a reaction that commonly occurs in
1. the Sun and other typical stars.
2. the ionosphere and thermosphere.
3. Earth’s outer core of molten iron.
4. a comet’s tail of ionized gases.
The surfaces of planet Mercury and our moon contain some very large craters that are most likely the result of
1. giant lava flows.
2. asteroid impacts.
3. nuclear explosions.
4. large collapsed caves.
The Sun is an average yellow star in the Milky Way galaxy, which is described as
1. a dwarf galaxy.
2. a spiral galaxy.
3. an elliptical galaxy.
4. an irregular galaxy.
As part of the modern theory of the origins of the elements, it is hypothesized that before the formation of the stars, most of the matter in the universe consisted of what atoms?
1. hydrogen and helium
2. nitrogen and carbon
3. silicon and lithium
4. uranium and radium
Scientific evidence suggests that magnesium is formed by stars during
1. photosynthesis.
2. the fission of carbon atoms.
3. nuclear fusion.
4. convection inside sunspots.
Stars begin their life cycle in
1. a black hole.
2. a nova.
3. a nebula.
4. a supernova.
Astronomers have discovered vast differences in stars through their observations. One theory used to explain these differences is that
1. the distances between stars are vast.
2. stars are at different points in their life cycles.
3. Earth’s atmosphere distorts our view of the stars.
4. there is too much light pollution on Earth to study stars.
An astronomer uses a telescope to observe a star. The color of the star indicates that it has a size and surface temperature similar to that of the Sun. Using this information, the astronomer can conclude that the star
1. is older than the Sun.
2. will survive for several billion years.
3. is moving very quickly away from Earth.
4. has a mass similar to the mass of Jupiter.
The final stage of a star’s existence is determined by its mass. The most massive stars will end their lives as
1. supergiant stars.
2. neutron stars.
3. white dwarf stars.
4. black holes.
Which of the following provides evidence for plate tectonics?
1. sea-floor topography
2. ocean currents
3. Coriolis effect
4. atmospheric temperatures
The youngest rocks on the ocean floor are typically located near what feature?
1. a mid-ocean ridge
2. a continental shelf
3. an abyssal plain
4. a subduction trench
A rift valley is evidence of which kind of plate boundary?
1. convergent
2. divergent
3. transform
4. uniform
The convergence of two continental plates would produce
1. island arcs.
2. rift valleys.
3. folded mountains.
4. trenches.
Which of the following is most responsible for the formation of new crust at the edge of a tectonic plate?
1. mountain building at a continent-continent convergent boundary
2. magma rising up from the mantle at a divergent boundary
3. two tectonic plates sliding past one another at a transform boundary
4. subduction of one oceanic plate under another at a convergent boundary
It is generally true that igneous rocks
1. contain primarily evaporites.
2. can be scratched with a penny.
3. normally contain fossils.
4. are composed of silicate minerals.
Relative cooling rates of igneous intrusive rocks can be estimated by comparing rocks’
1. crystal sizes.
2. composition.
3. density.
4. chemical reactivity.
Which of the following is most likely to produce a fragmental sedimentary rock?
1. magma fractured on the ocean floor
2. calcite crystallized from seawater
3. gravel deposited in a silt bed
4. limestone dissolved in cave formation
Earthquake vibrations are detected, measured, and recorded by instruments called
1. sonargraphs.
2. seismographs.
3. Richter scales.
4. magnetometers.
At which location would earthquakes be least likely to occur?
1. 1
2. 2
3. 3
4. 4
The Richter scale measures which of the following earthquake characteristics?
1. intensity
2. magnitude
3. frequency
4. probability
Which type of volcano would be the least explosive?
1. cinder cone
2. stratovolcano
3. shield volcano
4. composite cone
Which of the following energy sources is most likely to be abundant in California due to its position on a plate boundary?
1. wind
2. nuclear
3. solar
4. geothermal
What energy resource is made possible by the volcanic activity in California?
1. hydroelectricity
2. nuclear power
3. geothermal energy
4. solar energy
Geothermal energy is possible where there is
1. wind.
2. oil.
3. coal.
4. magma.
The Long Valley Caldera in east-central California was formed by a massive volcanic eruption about 760,000 years ago. Since then, it has erupted several times. Of the following, which would be least likely to indicate that another eruption will soon occur?
1. recurring earthquakes in the vicinity
2. decreases in precipitation in the area
3. changes in gas emissions from the caldera
4. uplifting of the floor of the caldera
Earthquake activity in California is primarily caused by
1. the lowering of aquifer levels.
2. the interaction of tides with the coast.
3. mining activity during the nineteenth century.
4. plates grinding past each other along active faults.
Landslides in California are caused by a combination of environmental factors, such as heavy precipitation, and geologic factors, such as
1. karst topography and poor drainage.
2. crust folding and artesian springs.
3. reverse faulting and perched water tables.
4. steep topography and unstable soil structure.
The main purpose of the California aqueduct is to
1. allow inexpensive water routes for transporting commercial products.
2. transport fresh water to areas with dense populations.
3. divert floodwater from populated regions to sparsely populated areas.
4. provide abundant ocean water to drier regions of California.
Water is important to many different types of industry. Which industry’s water requirement is the greatest burden on California’s fresh water supply?
1. aerospace
2. manufacturing
3. tourism
4. agriculture
The majority of freshwater in California is used for
1. drinking.
2. agriculture.
3. livestock.
4. fire fighting.
Only about 50% of the solar energy directed toward Earth penetrates directly to the surface. What happens to the rest of the radiation?
1. It is absorbed or reflected by the atmosphere.
2. It loses energy traveling through space.
3. It is reflected off the Moon and back into space.
4. It loses energy overcoming the Sun’s gravity.
Geothermal energy, a possible energy resource, is based on which phenomenon?
1. There are concentrations of heat in some places of Earth’s crust.
2. Earth’s internal energy heats its surface more than the Sun does.
3. Heat energy from the Sun penetrates deep into Earth.
4. Human activity is the largest source of heat energy on Earth.
The Moon is very hot on the side facing the Sun and very cold on the dark side. This extreme temperature difference is primarily due to the Moon’s
1. mineral composition.
2. thin atmosphere.
3. reflective rocks.
4. lack of volcanic activity.
Venus is warmed by solar radiation, but its thick cloud cover increases the temperature because the clouds
1. prevent the escape of heat into space.
2. convert solar radiation into heat.
3. absorb short light wavelengths, leaving heat.
4. produce heat as they are pushed by strong winds.
Which of these could increase average global temperatures?
1. increased use of fossil fuels
2. increased ocean algal blooms
3. decreased carbon dioxide emissions
4. increased numbers of animal species
The clouds that surround Venus are so thick that the planet actually absorbs less sunlight than the Earth. Nevertheless, Venus has a surface temperature of more than 400°C. Which of these best explains this high surface temperature?
1. The bright surfaces of the clouds reflect sunlight back on the planet.
2. The strong winds in the atmosphere produce friction.
3. The thick clouds in the atmosphere prevent heat from escaping.
4. The sulfuric acid in the clouds releases heat energy.
Permanent deforestation can contribute to potential global warming by
1. decreasing atmospheric CO₂ levels.
2. increasing atmospheric CO₂ levels.
3. decreasing atmospheric N₂ levels.
4. increasing atmospheric N₂ levels.
More solar energy reaches the equatorial regions than the polar regions because the equatorial regions
1. are covered by a greater area of land.
2. have more vegetation to absorb sunlight.
3. have days with more hours of light.
4. receive sun rays closest to vertical.
Which diagram best models the movement of coastal air during the afternoon?
What is the driving force for surface ocean currents?
1. density layering
2. global winds
3. the Coriolis effect
4. salt concentration
What causes the wind deflection from the north and south poles?
1. the rotation of Earth on its axis
2. the oblate shape of Earth
3. the tilt of Earth’s axis relative to its orbital plane
4. the difference in total land mass of the two hemispheres
Air moving from the poles toward the equator turns west. The primary cause of this global deflection is
1. the shape and size of land masses.
2. larger cities surrounded by farmlands.
3. changes in the magnetic field.
4. the rotation of the planet.
Earth rotates in an easterly direction. Therefore, southward wind currents in the Northern Hemisphere appear to be deflected to the
1. east.
2. west.
3. north.
4. south.
When a layer of cool air at the surface of Earth is found under a layer of warmer air above it, the result is known as
1. the Coriolis effect.
2. the greenhouse effect.
3. a temperature inversion.
4. an upwelling.
Temperature inversions can occur when
1. hot air rises during the night and sinks during the day.
2. air is heated directly by solar radiation.
3. cool air becomes trapped below warm air.
4. places are warmer in winter than summer.
Ocean surface currents are created by
1. differences in water temperature.
2. differences in water density.
3. friction with winds.
4. salinity variations.
At which location on the map would a rain forest most likely be found?
1. 1
2. 2
3. 3
4. 4
Where would deserts most likely be found on Planet X?
1. A
2. B
3. C
4. D
Which of these effects generally occurs as the result of a warm air mass and a cooler air mass converging at Earth’s surface?
1. The sky becomes clear.
2. Winds die down.
3. Cloud formation decreases.
4. Stormy weather patterns develop.
Snow on the ground prevents polar climates from gaining heat by what mechanism?
1. heating by greenhouse gases
2. heat spread from the equator
3. reflection of solar radiation
4. release of heat from Earth’s core
Shifts in Earth’s continents most likely caused a change in Earth’s
1. climatic regions.
2. mass.
3. orbital velocity.
4. atmospheric temperature.
The Gulf Stream in the Northern Hemisphere and the Brazilian Current in the Southern Hemisphere move poleward. Compared to inland areas at the same latitude, the coastal areas bordering these currents will
1. be warmer.
2. be more arid.
3. have more advection fogs.
4. have shorter growing seasons.
When comparing temperatures of two California regions of the same latitude, students found that the nighttime temperature dropped significantly at the desert site but only slightly at the coastal site. This difference is mostly caused by
1. lower wind speeds in the desert than at the coast.
2. less water vapor in the desert than at the coast.
3. lower carbon dioxide levels in the desert than at the coast.
4. less vegetation in the desert than at the coast.
Scientists have found fossils of tropical plants in Antarctica. How could tropical plants have grown in Antarctica?
1. At one time, Earth’s entire surface was a tropical rain forest.
2. At one time, Antarctica was located closer to the equator.
3. The rotation of Earth has increased, causing cooling of the atmosphere.
4. Catastrophic volcanic eruptions melted the ice and exposed the soil to sunlight.
Which of the following was made possible by the presence of photosynthetic bacteria on Earth?
1. a water cycle
2. an oxygen cycle
3. carbon fixation
4. anaerobic respiration
What piece of evidence supports the theory that volcanic eruptions formed Earth’s early atmosphere?
1. Volcanoes expel gases with chemical compositions which closely match the ratios of non-photosynthetic gases in air.
2. Volcanoes are clustered near the equator, so their gas output spreads over Earth’s surface.
3. Volcanoes expel a mixture of gases consisting almost entirely of water vapor and oxygen.
4. Volcanic eruptions are inversely proportional to local atmospheric pressure.
Which of these statements is best illustrated by this diagram?
1. Animals under water eat plants.
2. Land animals exhale oxygen into water.
3. Water-dwelling animals breathe carbon dioxide.
4. Plants can take in carbon dioxide from air or water.
From Earth’s atmosphere, carbon dioxide is used by plants, algae, and cyanobacteria during the process of
1. photosynthesis.
2. respiration.
3. decomposition.
4. nitrogen fixation.
The table above lists the gases coming from a modern Hawaiian volcano. If ancient volcanoes gave off the same gases, which gas would have been most helpful in the development of early life-forms that could carry out photosynthesis?
1. N₂
2. SO₂
3. CO₂
4. Cl₂
Carbon in the atmosphere is most often found as which of the following compounds?
1. stratospheric ozone
2. fossil fuel
3. carbon monoxide
4. carbon dioxide
Which of the following processes puts carbon from a forest floor back into the atmosphere?
1. combustion
2. photosynthesis
3. evaporation
4. transpiration
The release of carbon from limestone reservoirs into the atmosphere is most often accomplished by the
1. abrasion of the limestone by wind-blown sands.
2. destruction of limestone by lichens.
3. formation of stalagmites and stalactites in limestone caves.
4. chemical reaction between limestone and rainwater.
During periods of increased global temperatures, which of the following is most likely to occur?
1. a decrease in atmospheric CO₂
2. an increase in atmospheric CO₂
3. a decrease in earthquakes
4. an increase in earthquakes
Earth’s atmosphere is divided into layers that are based upon their
1. water content.
2. relative humidity.
3. gas content.
4. temperature gradient.
According to many scientists, what process led to the formation of the early atmosphere of Earth?
1. outgassing
2. metamorphism
3. asteroid collision
4. galactic dust
According to scientists, which of the following material categories is thought to be the primary cause for the depletion of the ozone layer?
1. chlorofluorocarbons
2. coal-containing sulfur
3. fossil fuels
4. hydrocarbons
The diagram above shows four layers of Earth’s atmosphere. Which of the following correctly labels the layers represented by A, B, C, and D (from Earth moving upward) in the correct sequence?
1. troposphere, stratosphere, mesosphere, thermosphere
2. thermosphere, mesosphere, stratosphere, troposphere
3. troposphere, mesosphere, thermosphere, stratosphere
4. mesosphere, troposphere, thermosphere, stratosphere
The primitive atmosphere of Earth was deficient in free oxygen. What process was primarily responsible for the development of the present percentage of free oxygen in the Earth’s atmosphere?
1. outgassing
2. photosynthesis
3. volcanic eruptions
4. oxidation of iron-based minerals
Most of the molecular oxygen in the early atmosphere of Earth resulted from
1. photosynthesis in primitive plants.
2. decaying primitive plants and animals.
3. volcanic eruptions.
4. lightning striking Earth.
The first atmosphere that formed above Earth was most likely due to what process?
1. eruption of volcanoes
2. movement of water
3. development of land plants
4. occurrence of violent storms
Which of the following human activities reduces the level of ozone in the atmosphere?
1. using artificial lighting in scientific polar stations
2. using large banks of solar cells for energy production
3. releasing chlorofluorocarbons from aerosol cans
4. destroying large areas of the equatorial rain forests

Earth Science - California Standards Tests (CSTs) Released Items

Choose the correct answer for each question.

A day on Saturn takes about 10 Earth hours. Which fact would best explain this short day?

The highest elevation on this topographic map can be no more than about

In an area where a river has cut deep into Earth, there are several layers of very different rock exposed. The oldest rock layer is most likely to be the layer that is

A student models an impact crater on the Moon by dropping a marble from a known height onto a pan of smooth flour. Before reaching any conclusions about the results of this simple experiment, the student repeats the activity several times so that

The existence of extraterrestrial life may never be proven, but this idea will become more scientifically acceptable over time if

An astronomer notes the change in position of Mars over several nights and then calculates that Mars orbits the Sun once every 400 Earth days. This figure is considerably lower than the 687 Earth-day orbit that is widely accepted for Mars. The scientist should

Which of the following statements best describes how the planets of the solar system formed?

Which planet was formed from the light gases of the outer solar nebula?

The diameter of Saturn is almost ten times that of the Earth, yet its density is much less. This can best be explained by the fact that Saturn

Evidence suggests that Earth is about 4.6 billion years old, even though no Earth rocks have been found that can be dated at more than 4 billion years old. This discrepancy is most likely caused by Earth’s original crust being

It has been determined that the oldest rocks retrieved from the Moon by Apollo astronauts were formed 4.44 billion years ago, while the oldest rocks found on Earth are less than 4 billion years old. This difference is most likely because

Before humans visited the Moon and brought back lunar rocks, the age of the Moon was unknown. Radioisotope dating of these rocks showed that the age of the oldest lunar rock was closest to

Which of the following is the best evidence that Earth’s continents were once in vastly different positions than they are today?

Early telescopes showed stars as only points of light, while the planets appeared to be much larger, providing evidence that stars must

Although many ancient civilizations designated certain patterns of stars as constellations, they never included planets in their constellations. What feature of planets, as opposed to stars, explains this?

Before the telescope was invented, people had the idea that the planets were closer to Earth than were the stars. Which piece of evidence contributed to this conclusion?

What is the source of energy for the Sun?

Fusion is a form of nuclear reaction resulting in an enormous release of heat energy. The fusion of hydrogen to helium is a reaction that commonly occurs in

The surfaces of planet Mercury and our moon contain some very large craters that are most likely the result of

The Sun is an average yellow star in the Milky Way galaxy, which is described as

As part of the modern theory of the origins of the elements, it is hypothesized that before the formation of the stars, most of the matter in the universe consisted of what atoms?

Scientific evidence suggests that magnesium is formed by stars during

Stars begin their life cycle in

Astronomers have discovered vast differences in stars through their observations. One theory used to explain these differences is that

An astronomer uses a telescope to observe a star. The color of the star indicates that it has a size and surface temperature similar to that of the Sun. Using this information, the astronomer can conclude that the star

The final stage of a star’s existence is determined by its mass. The most massive stars will end their lives as

Which of the following provides evidence for plate tectonics?

The youngest rocks on the ocean floor are typically located near what feature?

A rift valley is evidence of which kind of plate boundary?

The convergence of two continental plates would produce

Which of the following is most responsible for the formation of new crust at the edge of a tectonic plate?

It is generally true that igneous rocks

Relative cooling rates of igneous intrusive rocks can be estimated by comparing rocks’

Which of the following is most likely to produce a fragmental sedimentary rock?

Earthquake vibrations are detected, measured, and recorded by instruments called

At which location would earthquakes be least likely to occur?

The Richter scale measures which of the following earthquake characteristics?

Which type of volcano would be the least explosive?

Which of the following energy sources is most likely to be abundant in California due to its position on a plate boundary?

What energy resource is made possible by the volcanic activity in California?

Geothermal energy is possible where there is

The Long Valley Caldera in east-central California was formed by a massive volcanic eruption about 760,000 years ago. Since then, it has erupted several times. Of the following, which would be least likely to indicate that another eruption will soon occur?

Earthquake activity in California is primarily caused by

Landslides in California are caused by a combination of environmental factors, such as heavy precipitation, and geologic factors, such as

The main purpose of the California aqueduct is to

Water is important to many different types of industry. Which industry’s water requirement is the greatest burden on California’s fresh water supply?

The majority of freshwater in California is used for

Only about 50% of the solar energy directed toward Earth penetrates directly to the surface. What happens to the rest of the radiation?

Geothermal energy, a possible energy resource, is based on which phenomenon?

The Moon is very hot on the side facing the Sun and very cold on the dark side. This extreme temperature difference is primarily due to the Moon’s

Venus is warmed by solar radiation, but its thick cloud cover increases the temperature because the clouds

Which of these could increase average global temperatures?

The clouds that surround Venus are so thick that the planet actually absorbs less sunlight than the Earth. Nevertheless, Venus has a surface temperature of more than 400°C. Which of these best explains this high surface temperature?

Permanent deforestation can contribute to potential global warming by

More solar energy reaches the equatorial regions than the polar regions because the equatorial regions

Which diagram best models the movement of coastal air during the afternoon?

What is the driving force for surface ocean currents?

What causes the wind deflection from the north and south poles?

Air moving from the poles toward the equator turns west. The primary cause of this global deflection is

Earth rotates in an easterly direction. Therefore, southward wind currents in the Northern Hemisphere appear to be deflected to the

When a layer of cool air at the surface of Earth is found under a layer of warmer air above it, the result is known as

Temperature inversions can occur when

Ocean surface currents are created by

At which location on the map would a rain forest most likely be found?

Where would deserts most likely be found on Planet X?

Which of these effects generally occurs as the result of a warm air mass and a cooler air mass converging at Earth’s surface?

Snow on the ground prevents polar climates from gaining heat by what mechanism?

Shifts in Earth’s continents most likely caused a change in Earth’s

The Gulf Stream in the Northern Hemisphere and the Brazilian Current in the Southern Hemisphere move poleward. Compared to inland areas at the same latitude, the coastal areas bordering these currents will

When comparing temperatures of two California regions of the same latitude, students found that the nighttime temperature dropped significantly at the desert site but only slightly at the coastal site. This difference is mostly caused by

Scientists have found fossils of tropical plants in Antarctica. How could tropical plants have grown in Antarctica?

Which of the following was made possible by the presence of photosynthetic bacteria on Earth?

What piece of evidence supports the theory that volcanic eruptions formed Earth’s early atmosphere?

Which of these statements is best illustrated by this diagram?

From Earth’s atmosphere, carbon dioxide is used by plants, algae, and cyanobacteria during the process of

The table above lists the gases coming from a modern Hawaiian volcano. If ancient volcanoes gave off the same gases, which gas would have been most helpful in the development of early life-forms that could carry out photosynthesis?

Carbon in the atmosphere is most often found as which of the following compounds?

Which of the following processes puts carbon from a forest floor back into the atmosphere?

**A day on Saturn takes about 10 Earth hours. Which fact would best explain this short day?**

**In an area where a river has cut deep into Earth, there are several layers of very different rock exposed. The oldest rock layer is most likely to be the layer that is**

**Which of the following statements best describes how the planets of the solar system formed?**

**The diameter of Saturn is almost ten times that of the Earth, yet its density is much less. This can best be explained by the fact that Saturn**

**Which of the following is most responsible for the formation of new crust at the edge of a tectonic plate?**

**At which location would earthquakes be least likely to occur?**

**Which type of volcano would be the least explosive?**

**Which of the following energy sources is most likely to be abundant in California due to its position on a plate boundary?**

**Which diagram best models the movement of coastal air during the afternoon?**

**At which location on the map would a rain forest most likely be found?**

**Where would deserts most likely be found on Planet X?**

**Shifts in Earth’s continents most likely caused a change in Earth’s**

**Which of these statements is best illustrated by this diagram?**

**Carbon in the atmosphere is most often found as which of the following compounds?**

**The release of carbon from limestone reservoirs into the atmosphere is most often accomplished by the**

**During periods of increased global temperatures, which of the following is most likely to occur?**

**The first atmosphere that formed above Earth was most likely due to what process?**