Name: ___________________________________    Date: ______________



1.
What mechanism forms the magnetospheres around several of the planets?
A.
the gravitational force of attraction of the other planets on the planetary upper atmosphere
B.
the very rapid spin of these planets, spinning the atmosphere outward
C.
repulsion of solar electromagnetic radiation by the planetary magnetic field
D.
repulsion of the solar wind by the planetary magnetic field


2.
What relationship must exist between a certain molecule's average speed, v, in a planetary atmosphere and the escape velocity, Vesc, from the planet's surface for this particular molecular species to be retained by the planet?
A.
v should not exceed Vesc
B.
v must be less than about 6 × Vesc
C.
v must be less than about 1/6 Vesc
D.
v should not exceed 2 × Vesc


3.
Earth's magnetic field is caused by
A.
electric currents flowing in the molten core.
B.
the motion of the electrically charged particles of the solar wind as they pass Earth.
C.
a solid iron magnet in its interior.
D.
electric currents flowing in the ionospheric layer of its atmosphere.


4.
Energy calculations that simply equate the influx of solar energy on Earth with the outflow of energy from Earth lead to a very low average equilibrium temperature for Earth, of around –27°C or –16°F, which is much lower than the actual average surface temperature of Earth, +9°C or 48°F. What mechanism explains this discrepancy between the simple prediction and observation?
A.
kinetic energy of meteoritic material that is dissipated in the atmosphere as the particles are stopped by friction
B.
chemical action between molecules in Earth's atmosphere
C.
the greenhouse effect—the capture by gases in the atmosphere of heat radiation that would otherwise escape
D.
extra energy conducted outward from the hot interior of Earth


5.
A typical asteroid is made of
A.
ices of water, methane, and ammonia or perhaps ices with dust-sized grains of rock mixed in.
B.
ice with a liquid water core.
C.
rock and metal.
D.
rock and ice.


6.
Where in the universe are heavy elements with masses greater than that of helium being produced at this time?
A.
dark clouds of dust and gas
B.
central cores of stars
C.
event horizons of massive black holes
D.
surface layers of stars


7.
Suppose that in 2008, the Hubble Space Telescope discovers a series of planets with the following characteristics moving around a star resembling our Sun: spherical, solid surfaces; mean densities about four times that of H2O; radii about 4000 km; low-density atmospheres. How would these planets be classified in terms of our solar system?
A.
Jovian planets
B.
cometary nuclei
C.
asteroids
D.
terrestrial planets


8.
The reason the primary mirror of an astronomical telescope is often polished to a parabolic shape is
A.
to avoid the chromatic aberration that would be produced by an equivalent spherical mirror.
B.
that it is lighter and easier to mount in a telescope.
C.
that it is easier to produce, even though the resulting mirror will produce more spherical aberration than an equivalent spherical mirror.
D.
to avoid spherical aberration.


9.
The parameter of an atom that defines its unique position in the periodic table is
A.
the total number of protons and neutrons in the nucleus.
B.
its temperature.
C.
the number of protons in the nucleus.
D.
its size.


10.
The wavelength of infrared radiation is longer than visible light and is usually measured in units of micrometers. One micrometer (µm) is
A.
10–3 m.
B.
106 m.
C.
10–6 m.
D.
10–9 m.


11.
The setting Sun appears red because
A.
its light is scattered by a thicker layer of air than during the day.
B.
red light is more refracted around the horizon than is blue light.
C.
the Sun is cooler in the evening.
D.
red light is more diffracted around the horizon than is blue light.


12.
The atomic number that designates the position of an element in the periodic table is equal to the
A.
number of the column in which the element is placed in the periodic table.
B.
number of protons in the nucleus of the atom.
C.
number of neutrons in the nucleus of the atom.
D.
sum of the number of neutrons and protons in the nucleus of the atom.


13.
Atoms in a hot, low-density gas (e.g., in a laboratory-type spectral source) emit a spectrum that is
A.
a series of specific colors at the same wavelengths, independent of the type of atom excited.
B.
a series of specific colors, whose positions change as the gas temperature changes.
C.
continuous over all visible wavelengths, with maximum intensity in the blue.
D.
a series of specific colors, unique to the type of atom in the tube, but fixed in position even when the gas temperature changes.


14.
Which of the following characteristics is not typical of our planetary system?
A.
The orbits of most planets are almost circular.
B.
Most planets have about the same physical size.
C.
The spin axes of most planets are aligned to within 30° to the perpendicular to the orbital plane.
D.
Most planets orbit the Sun in the same direction.


15.
If carbon dioxide (CO2) was much more abundant in Earth's early atmosphere, what happened to most of this gas?
A.
It was dissociated by lightning into its components, carbon and oxygen, which then escaped from Earth's gravity.
B.
It escaped into space because of its low molecular weight.
C.
It combined with other substances to produce carbonate rocks in limestone.
D.
It was dissociated by the ultraviolet radiation in sunlight, the carbon settling onto Earth while the oxygen remained in the atmosphere to support life.


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