The Earth was formed by collisions of progressively bigger objects which led to
A. heating, melting and differentiation in that order.
B. heating, melting and evaporation.
C. melting, accretion and differentiation.
D. heating, differentiation and melting in that order.
ANSWER: 

Which of the following is incorrect concerning the present magnetic field of the Earth?
A. The magnetic field is created in the Earth's molten, outer core.
B. The orientation of the magnetic field moves slightly.
C. The north magnetic pole is lined up with the north geographical pole.
D. Motion in the Earth's liquid core probably creates the magnetism.
ANSWER: 

We have found out about the structure of the deep interior of the Earth by
A. deep sea drilling projects.
B. drilling on land as well as the ocean bottom.
C. sending x-rays through the Earth.
D. seismology which interprets the way earthquake waves bounce around inside the Earth. 
ANSWER: 

Plates on the surface of the Earth are perhaps moved by convection in the
A. mantle driven by heat from radioactive uranium and other metals.
B. core driven by heat from radioactive uranium and other metals.
C. outer core driven by a hot, inner core.
D. mantle driven by heat from earthquake activity.
ANSWER: 

The best place to look for evidence of the movement of plates is
A. on the ocean floor near mid-oceanic ridges.
B. on continents near mountains.
C. in the upper, stressed area of the mantle.
D. near large volcanic mountain chains.
ANSWER: 

Choose the incorrect statement concerning volcanic activity on Earth.
A. Volcanic eruptions have obliterated some of the cratering record on Earth.
B. Old evidence of surface conditions have been destroyed by volcanism.
C. Volcanism has produced mountain chains and "hotspots."
D. Volcanic rock usually rise from hundreds of miles down in the Earth.
ANSWER: 

The changes on the Earth's surface and the associated recycling processes
A. are fewer than on other planets.
B. seem to lack subduction.
C. is part of a continuous recycling system that makes it unique.
D. rely totally on the atmosphere.
ANSWER: 

Liquid water can exist on Earth because of
A. the mass of the Earth.
B. its distance from the sun.
C. the strong magnetic field that pulled water to the surface during its formation.
D. its rather thin atmosphere.
ANSWER: 

Which of the following was probably the least important in creating the Earth's oceans?
A. Water was part of the chemical make-up of early particles (planetesimals) that accreted.
B. The solar wind pushed water vapor towards Earth where it became trapped by gravity.
C. Volcanoes brought water vapor and other gases out of the Earth.
D. Comets have brought water to Earth as the result of collisions over geologic time.
ANSWER: 

The Earth and Venus both had abundant amounts of primordial carbon dioxide (CO2), the Earth has changed but Venus is now very hot because (see Helps & Hints)
A. it lacked a large ocean to interact with the CO2 and convert it to limestone.
B. its thin atmosphere allows the sun to heat the surface more intently.
C. it received more CO2 during its formation than the Earth.
D. its gravitational field trapped more CO2.
ANSWER: 

Choose the incorrect statement concerning the surface temperature of the Earth.
A. The surface temperature of the Earth is maintained by the water vapor and CO2 creating a Greenhouse effect in the atmosphere.
B. Without Greenhouse gases, the Earth's average temperature would be several degrees below zero.
C. A large proportion of the Earth's surface temperature comes from the Earth's hot interior.
D. As the amount of CO2 in the Earth's atmosphere rises, the Earth's surface temperature should also rise.
ANSWER: 

Ozone plays a vital role in
A. protecting life on Earth by absorbing harmful ultraviolet energy.
B. protecting life on Earth by regulating the amount of CO2 in the atmosphere.
C. helping life on Earth by regulating the amount of photosynthesis on the surface.
D. protecting life on Earth by creating part of the oxygen in the atmosphere.
ANSWER: 

21 " The Moon and Mercury"

13. The large, dark areas that we can see on the moon
A. are cratered areas that reflect less light.
B. are broad plains made up of lava flows.
C. are highlands that reflect less light.
D. were formed about 500 million years ago.
ANSWER: 

The very intense bombardment of the moon that resulted in cratering
A. destroyed the moon's atmosphere.
B. made most of the surface darker.
C. also occurred on Earth and the other planets.
D. created a dust filled atmosphere.
ANSWER: 

The moon presently lacks an atmosphere because
A. the intense bombardment of its surface destroyed it.
B. the material that accreted to form the moon did not contain gases.
C. the great impact that created the moon also evaporated the atmosphere.
D. it is too small (that is, it doesn't have enough mass).
ANSWER: 

Counting craters on the surface of the moon gives an indication of
A. the size of the impacts.
B. the age of the surface.
C. the composition of the surface.
D. when the moon's protective atmosphere was lost.
ANSWER: 

The same side of the moon always faces the Earth because:
A. when the moon was created by the great impact, it stopped the moon's rotation.
B. when the moon was captured by the Earth, it stopped the moon's rotation.
C. its rate of rotation is equal to its rate of revolution.
D. its rate of rotation is slowing down.
ANSWER: 

Compared to the front side, the backside of the moon has a thicker crust,
A. is on the average higher and is covered by more lava.
B. has deeper craters and is covered by more lava.
C. has darker layers of rock and is covered by less lava.
D. is on the average higher and is covered by less lava.
ANSWER: 

Which of the following is true concerning the structure and composition of the moon?
A. The density of the moon is about the same as the Earth's mantle; it doesn't have a large iron core.
B. Moon rocks are like heated rock from the Earth's mantle; it also has a large iron core.
C. The density of the moon is about the same as the Earth's mantle; it also has a large iron core.
D. Moon rocks are like heated rock from the Earth's crust; it doesn't have a large iron core.
ANSWER: 

Comparing Mercury with other objects we can say that
A. Mercury is a lot like the moon on its outside but more like the Earth on the inside.
B. Mercury is a lot like the moon on its surface but its volcanoes are more like those on Mars.
C. Mercury is a lot like the moon both on its surface as well as its interior.
D. Mercury lacks the large lava plains of the lunar surface but it is like the moon on the inside.
ANSWER: 

Mercury's diameter is
A. larger than the moons but its density is about the same as the Earths.
B. smaller than the moons but its density is about the same as the Earths.
C. smaller than the Earths and its density is about the same as the moons.
D. smaller than the Earths and its mass is about the same as the moons.
ANSWER: 

The disproportionate amount of influence Mercury has had on the orbits of some asteroids indicates that
A. it has a strong magnetic field.
B. it has a lot of mass for its size (diameter).
C. it was once closer to these asteroids.
D. the asteroids were very dense.
ANSWER: 

The density of Mercury indicates a/an
A. average size iron core.
B. very large iron core for its diameter.
C. very fast rotational rate.
D. thick mantle.
ANSWER: 

The discovery of a weak magnetic field around Mercury probably indicates a/an
A. dynamo in the mantle.
B. average rotational rate.
C. iron core that is still partially molten.
D. large mass for its diameter.
ANSWER: 

Which of the following is not true concerning Mercury?
A. It is very hot at the equator.
B. It is rotating very slowly compared to the Earth.
C. It lacks seasons due to its slow rotation.
D. It probably has small amounts of frozen water near its poles.
ANSWER: 
