Chapter 2 (GEOL107)

The geothermal gradient Choose one: A. is the rate of change in temperature with depth in the Earth. B. increases exponentially as you go deeper into the Earth. C. averages about 5°C per kilometer in the upper crust. D. indicates that temperatures near the mantle-core boundary may exceed the temperature of the Sun (5,500°C).

A. is the rate of change in temperature with depth in the Earth.

What are the two most common components of Earth's atmosphere? A. nitrogen and oxygen B. oxygen and carbon dioxide C. nitrogen and argon D. argon and oxygen E. carbon dioxide and water vapor

A. nitrogen and oxygen

The Earth's magnetic field is generated in the Choose one: A. outer core. B. upper mantle. C. crust. D. inner core.

A. outer core.

Which of the following categories of materials is part of the Earth's makeup? Choose one: A. volatiles, materials that easily become gases at ordinary Earth surface temperatures B. organic chemicals, all calcium-containing compounds C. melts, liquid materials that have vaporized due to heat to form a gas D. alloys, mixtures of more than one type of mineral

A. volatiles, materials that easily become gases at ordinary Earth surface temperatures

Continental crust Choose one: A. is more mafic than oceanic crust. B. is thinner than oceanic crust. C. is denser than oceanic crust. D. is thinnest beneath zones of stretching, called rifts.

D. is thinnest beneath zones of stretching, called rifts.

The two most common gases of the Earth's atmosphere, and their percentages, are Choose one: A. oxygen (O2), 21%; and carbon dioxide (CO2), 78%. B. water (H2O), 21%; and oxygen (O2), 78%. C. carbon dioxide (CO2), 21%; and oxygen (O2), 78%. D. nitrogen (N2), 78%; and oxygen (O2), 21%.

D. nitrogen (N2), 78%; and oxygen (O2), 21%.

Which of the following is caused by the interaction of the solar wind with magnetic lines of force and gases in polar regions? Choose one: A. the Van Allen belts B. the heliosphere C. a dipole D. the aurorae

D. the aurorae

Peridotite is Choose one: A. extremely abundant at the Earth's surface. B. felsic. C. poor in iron and magnesium, and rich in silica. D. the most abundant rock in the Earth.

D. the most abundant rock in the Earth.

Earthquakes are generated Choose one: A. by the Earth's magnetic field. B. only in the mantle. C. as pressure and temperature increase with depth in the Earth. D. when rock moves along faults.

D. when rock moves along faults.

Identify the true statement. Choose one: A. The temperature at the Earth's center may almost equal the temperature of the Sun's surface. B. The calculated density at the Earth's center makes scientists almost certain that the inner core is composed of diamond. C. The geothermal gradient is the rate of change in pressure with depth in the Earth. D. The pressure at the Earth's center is less than 300 times greater than normal atmospheric pressure.

A. The temperature at the Earth's center may almost equal the temperature of the Sun's surface.

Which of the following statements about density is true? Choose one: A. Felsic rock is denser than mafic rock. B. The Earth's density is a little over 5 g/cm3. C. Changes in density can be detected by changes in seismic-wave intensity. D. The density of crustal rock is between 5 and 7.9 g/cm3.

B. The Earth's density is a little over 5 g/cm3.

Which of the following trap(s) cosmic rays and shield(s) life on the Earth from excessive radiation? Choose one: A. Oort Cloud B. Van Allen belts C. asteroid belt D. Kuiper Belt

B. Van Allen belts

Boundaries between the Earth's layers Choose one: A. occur because of tides. B. are places where there is an abrupt change in the density of rock. C. are noted by the changing metal content of each layer. D. are defined by abrupt changes in earthquake density.

B. are places where there is an abrupt change in the density of rock.

Studies of interplanetary space have indicated that Choose one: A. the planets in our Solar System do not orbit within the same plane. B. interplanetary space is much denser than interstellar space. C. the Earth's magnetic field is spherical. D. both Mars and Venus lie within our Solar System's habitable zone.

B. interplanetary space is much denser than interstellar space.

Which of the Earth's layers accounts for most of the volume of the Earth? Choose one: A. inner core B. mantle C. crust D. lithosphere

B. mantle

An astronomical unit (AU) represents the distance between the Earth and which celestial body? A. the Moon B. the Sun C. Polaris D. Mars E. Pluto

B. the Sun

Identify the true statement. Choose one: A. Hot, molten rock that cools and hardens produces metamorphic rocks. B. Igneous rocks form when pre-existing rocks undergo changes in response to heat and pressure. C. Magma is the term for very hot rock that is molten; when it cools and hardens, it's called lava. D. Sedimentary rocks form when pre-existing rock grains are cemented together.

D. Sedimentary rocks form when pre-existing rock grains are cemented together.

Which of the following would you consult to predict the effect of sea-level changes on the amount of exposed land areas? Choose one: A. seismic velocity graphs B. readings of a magnetosphere C. the ship's log of the Glomar Challenger D. a hypsometric curve

D. a hypsometric curve

Rocks Choose one: A. form under intense heat and pressure. B. are an accumulation of loose grains that have not been cemented together. C. are solids in which atoms are not arranged in an orderly pattern. D. can be an aggregate (mixture) of minerals.

D. can be an aggregate (mixture) of minerals.

Meteoroids Choose one: A. are made of fragments of asteroids and comets and include chips of Jupiter and Saturn. B. that explode into fireballs are termed chondrites. C. are bits of icy space debris with long tails that orbit the Sun. D. can travel at speeds fast enough to cause the object to glow ("shooting stars").

D. can travel at speeds fast enough to cause the object to glow ("shooting stars").

Choose the list that accurately shows rock composition decreasing in silica and increasing in iron and magnesium. Choose one: A. granite, peridotite, basalt B. peridotite, basalt, granite C. basalt, peridotite, granite D. granite, basalt, peridotite

D. granite, basalt, peridotite

Which of the following groups of elements make up most of the mass of the whole Earth? Choose one: A. silicon, iron, potassium, and sodium B. nitrogen, oxygen, helium, and carbon dioxide C. magnesium, iron, carbon dioxide, and argon D. iron, oxygen, silicon, and magnesium

D. iron, oxygen, silicon, and magnesium

The crust Choose one: A. can be separated into two types: lithosphere and asthenosphere. B. is the top of the mantle that has cooled and hardened. C. plus the upper part of the mantle make up the asthenosphere. D. is separated from the mantle by the Moho.

D. is separated from the mantle by the Moho.