Astronomy midterm 3

If you have a 100-watt light bulb, how much energy does it use each minute?

A) 6,000 joules

B) 6,000 watts

C) 600 joules

D) 600 watts

E) 100 joules

6,000 joules

If a material is highly opaque, then it

A) reflects most light.

B) absorbs most light.

C) transmits most light.

D) scatters most light.

E) emits most light.

absorbs most light

When light reflects off an object, what is the relation between the angle of incidence and the angle of reflection?

A) angle of incidence = angle of reflection

B) angle of incidence + angle of reflection = 90°

C) angle of incidence + angle of reflection = 180°

D) angle of incidence - angle of reflection = 90°

E) It depends on the material that the light reflects off.

angle of incidence = angle of reflection

If a material is transparent, then it

A) reflects light well.

B) absorbs light well.

C) transmits light well.

D) scatters light well.

E) emits light well.

transmit light well

Grass (that is healthy) looks green because

A) it emits green light and absorbs other colors.

B) it absorbs green light and emits other colors.

C) it transmits green light and emits other colors.

D) it reflects green light and absorbs other colors.

it reflects green light and absorbs other colors.

Everything looks red through a red filter because

A) the filter emits red light and absorbs other colors.

B) the filter absorbs red light and emits other colors.

C) the filter transmits red light and absorbs other colors.

D) the filter reflects red light and transmits other colors.

the filter transmits red light and absorbs other colors.

Which of the following cannot be described by a field?

A) gravitational forces

B) electrical forces

C) magnetic forces

D) radiation pressure

radiation pressure

The frequency of a wave is

A) the number of peaks passing by any point each second.

B) measured in cycles per second.

C) measured in hertz (Hz).

D) equal to the speed of the wave divided by the wavelength of the wave.

E) all of the above

all of the above

The wavelength of a wave is

A) how strong the wave is.

B) the distance between a peak of the wave and the next trough.

C) the distance between two adjacent peaks of the wave.

D) the distance between where the wave is emitted and where it is absorbed.

E) equal to the speed of the wave times the wave's frequency.

the distance between two adjacent peaks of the wave.

How are wavelength, frequency, and energy related for photons of light?

A) Longer wavelength means lower frequency and lower energy.

B) Longer wavelength means higher frequency and lower energy.

C) Longer wavelength means higher frequency and higher energy.

D) Longer wavelength means lower frequency and higher energy.

E) There is no simple relationship because different photons travel at different speeds.

Longer wavelength means lower frequency and lower energy.

From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?

A) infrared, visible light, ultraviolet, X rays, gamma rays, radio

B) radio, infrared, visible light, ultraviolet, X rays, gamma rays

C) visible light, infrared, X rays, ultraviolet, gamma rays, radio

D) gamma rays, X rays, visible light, ultraviolet, infrared, radio

E) radio, X rays, visible light, ultraviolet, infrared, gamma rays

radio, infrared, visible light, ultraviolet, X rays, gamma rays

From shortest to longest wavelength, which of the following correctly orders the different categories of electromagnetic radiation?

A) infrared, visible light, ultraviolet, X rays, gamma rays, radio

B) radio, infrared, visible light, ultraviolet, X rays, gamma rays

C) visible light, infrared, X rays, ultraviolet, gamma rays, radio

D) gamma rays, X rays, ultraviolet, visible light, infrared, radio

E) gamma rays, X rays, visible light, ultraviolet, infrared, radio

gamma rays, X rays, ultraviolet, visible light, infrared, radio

Which of the following statements about X rays and radio waves is not true?

A) X rays have shorter wavelengths than radio waves.

B) X rays and radio waves are both forms of light, or electromagnetic radiation.

C) X rays have higher frequency than radio waves.

D) X rays have higher energy than radio waves.

E) X rays travel through space faster than radio waves.

X rays travel through space faster than radio waves.

Which of the following statements about X rays and radio waves is not true?

A) Neither X rays nor radio waves can penetrate the earth's atmosphere.

B) X rays have shorter wavelengths than radio waves.

C) X rays and radio waves are both forms of light, or electromagnetic radiation.

D) X rays have higher frequency than radio waves.

E) X rays have higher energy than radio waves.

Neither X rays nor radio waves can penetrate the earth's atmosphere.

We can see each other in the classroom right now because we

A) emit thermal radiation.

B) emit visible light.

C) emit infrared light.

D) reflect visible light.

E) reflect infrared light.

reflect visible light.

Without telescopes or other aid, we can look up and see the Moon in the night sky because it

A) emits visible light.

B) emits thermal radiation.

C) reflects infrared light.

D) reflects visible light.

E) glows through radioactive decay.

reflects visible light.

How many atoms fit across the period at the end of this sentence?

A) hundreds

B) thousands

C) millions

D) billions

E) more than you could count in a lifetime

millions

What is a compound?

A) a group of molecules

B) a molecule containing hydrogen

C) a molecule containing two or more elements

D) an ionized molecule

E) a molecule containing carbon

a molecule containing two or more elements

Compared to the volume of its nucleus, the volume of an atom is about

A) the same.

B) a thousand times greater.

C) a million times greater.

D) a billion times greater.

E) a trillion times greater.

a trillion times greater.

How much electrical charge does an atom with 6 protons, 6 neutrons, and 5 electrons have?

A) a total charge of +17

B) a negative charge of -5

C) a positive charge of +7

D) a positive charge of +1

E) none of the above

a positive charge of +1

Which of the following statements about electrical charge is true?

A) Two negative charges will attract each other.

B) Two positive charges will attract each other.

C) A positive charge and a negative charge will repel each other.

D) A positive charge and a negative charge will attract each other.

A positive charge and a negative charge will attract each other.

Which of the following statements about electrons is not true?

A) Electrons orbit the nucleus rather like planets orbiting the Sun.

B) Within an atom, an electron can have only particular energies.

C) Electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels.

D) An electron has a negative electrical charge.

E) Electrons have very little mass compared to protons or neutrons.

Electrons orbit the nucleus rather like planets orbiting the Sun.

Suppose you built a scale-model atom in which the nucleus was the size of a tennis ball. About how far would the cloud of electrons extend?

A) several centimeters

B) a few meters

C) a few tens of meters

D) several kilometers

E) to the Sun

several kilometers

Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. What is its atomic number and atomic weight?

A) The atomic number is 79, and the atomic weight is 197.

B) The atomic number is 79, and the atomic weight is 118.

C) The atomic number is 118, and the atomic weight is 197.

D) The atomic number is 118, and the atomic weight is 79.

The atomic number is 79, and the atomic weight is 197.

Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. If it is doubly ionized, what is the charge of the gold ion and how many electrons remain in the ion?

A) The gold ion has a charge of +2 and 77 electrons.

B) The gold ion has a charge of +2 and 79 electrons.

C) The gold ion has a charge of -2 and 77 electrons.

D) The gold ion has a charge of +2 and 2 electrons.

E) The gold ion has a charge of +79 and no electrons.

The gold ion has a charge of +2 and 77 electrons.

Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms isotopes of each other?

A) Atom 1: nucleus with 6 protons and 8 neutrons, surrounded by 6 electrons

Atom 2: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons

B) Atom 1: nucleus with 8 protons and 8 neutrons, surrounded by 8 electrons

Atom 2: nucleus with 8 protons and 8 neutrons, surrounded by 7 electrons

C) Atom 1: nucleus with 92 protons and 143 neutrons, surrounded by 92 electrons

Atom 1: nucleus with 92 protons and 143 neutrons, surrounded by 92 electrons

Atom 2: nucleus with 92 protons and 146 neutrons, surrounded by 92 electrons

An atom of the element iron has an atomic number of 26 and an atomic weight of 56. If it is neutral, how many protons, neutrons, and electrons does it have?

A) 26 protons, 30 neutrons, 26 electrons

B) 26 protons, 30 neutrons, 30 electrons

C) 26 protons, 56 neutrons, 26 electrons

D) 13 protons, 43 neutrons, 13 electrons

E) 13 protons, 56 neutrons, 13 electrons

26 protons, 30 neutrons, 26 electrons

Oxygen has atomic number 8. How many times must an oxygen atom be ionized to create an O+5 ion, and how many electrons will the ion have?

A) It must be ionized three times; it now has five electrons.

B) It must be ionized five times; it now has five electrons.

C) It must be ionized five times; it now has three electrons.

D) It doesn't have to be ionized; it just needs to gain five protons.

E) It doesn't have to be ionized; it already has only three electrons.

It must be ionized five times; it now has three electrons.

At extremely high temperatures (e.g., millions of degrees), which of the following best describes the phase of matter?

A) a gas of rapidly moving molecules

B) a plasma consisting of positively charged ions and free electrons

C) a gas consisting of individual, neutral atoms, but no molecules

D) a plasma consisting of rapidly moving, neutral atoms

E) none of the above (At these extremely high temperatures, matter cannot exist.)

a plasma consisting of positively charged ions and free electrons

Sublimation is the process in which

A) molecules go from the solid phase to the liquid phase.

B) molecules go from the liquid phase to the gas phase.

C) molecules go from the solid phase to the gas phase.

D) electrons are stripped from atoms.

E) electrons are captured by ions.

molecules go from the solid phase to the gas phase.

Dissociation is the process in which

A) the bonds between atoms in a molecule are broken.

B) a molecule goes from the solid phase to the gas phase.

C) the bonds between electrons around an atomic nucleus are broken.

D) an element changes into another form.

E) an electron is shared between atomic nuclei.

the bonds between atoms in a molecule are broken.

When an atom loses an electron, it becomes

A) sublimated.

B) dissociated.

C) ionized.

D) an isotope.

E) a plasma.

ionized.

An atom in an excited state contains more of what type of energy than the same atom in the ground state?

A) mass-energy

B) kinetic energy

C) thermal energy

D) gravitational potential energy

E) electric potential energy

electric potential energy

When an atom absorbs a photon containing energy, any of the following can happen except which?

A) The atom becomes excited.

B) The atom is ionized.

C) An electron moves from an upper energy level to a lower one.

D) An electron moves from a lower energy level to an upper one.

An electron moves from an upper energy level to a lower one.

The loss of an electron from a neutral helium atom results in

A) neutral hydrogen.

B) ionized hydrogen.

C) ionized helium.

D) neutral deuterium.

E) ionized deuterium.

Ionized helium

An electron-volt is

an amount of energy much smaller than a joule.

The study of energy levels in atoms is called

quantum mechanics.

How can an electron in an atom lose energy to go from a higher energy level to a lower energy level?

It releases a photon equal in energy to its own energy drop.

If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces

an emission line spectrum.

When an electron in an atom goes from a higher energy state to a lower energy state, the atom

A) emits a photon of a specific frequency.

B) absorbs a photon of a specific frequency.

C) absorbs several photons of a specific frequency.

D) can emit a photon of any frequency.

E) can absorb a photon of any frequency.

emits a photon of a specific frequency.

When white light passes through a cool cloud of gas, we see

A) visible light.

B) infrared light.

C) thermal radiation.

D) an absorption line spectrum.

E) an emission line spectrum.

an absorption line spectrum.

Spectra from neutral atoms compared with spectra from ionized atoms of the same element

A) are the same.

B) are slightly redshifted.

C) are slightly blueshifted.

D) have different sets of spectral lines.

E) have the same sets of spectral lines but different widths for those lines.

have different sets of spectral lines.

Which of the following objects is not a close approximation of a thermal emitter?

A) hot, thin gas

B) a star

C) a filament in a light bulb

D) you

E) a planet

hot, thin gas

Thermal radiation is defined as

radiation that depends only on the emitting object's temperature.

A perfectly opaque object that absorbs all radiation and reemits the absorbed energy as thermal radiation is

A) a hot, dense cloud of gas.

B) a cold, dense cloud of gas.

C) an infrared radiation emitter.

D) a thermal emitter.

E) transparent.

a thermal emitter.

Which of the following statements about thermal radiation is always true?

A) A hot object emits more X rays than a cool object.

B) A hot object emits more radio waves than a cool object.

C) A hot object emits more total radiation than a cool object.

D) A hot object emits more total radiation per unit surface area than a cool object.

E) A hot object emits less total radiation than a cool object.

A hot object emits more total radiation per unit surface area than a cool object.

Which of the following statements about thermal radiation is always true?

A) A hot object emits photons with a longer wavelength than a cool object.

B) A hot object emits photons with a higher average energy than a cool object.

C) A hot object emits more radio waves than a cool object.

D) A hot object emits more X rays than a cool object.

A hot object emits photons with a higher average energy than a cool object.

If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits

A) 3 times more energy.

B) 9 times more energy.

C) 12 times more energy.

D) 81 times more energy.

E) none of the above

81 times more energy.

T^4

A gas heated to millions of degrees would emit

A) mostly radio waves.

B) mostly X rays.

C) mostly ultraviolet light.

D) an equal amount of all wavelengths of light.

E) no light, because it is too hot.

mostly X rays.

We can learn a lot about the properties of a star by studying its spectrum. All of the following statements are true except one. Which one?

A) The peak of the star's thermal emission tells us its temperature: Hotter stars peak at shorter (bluer) wavelengths.

B) The total amount of light in the spectrum tells us the star's radius.

C) We can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals.

D) We can look at Dopple

The total amount of light in the spectrum tells us the star's radius.

The spectra of most galaxies show redshifts. This means that their spectral lines

have wavelengths that are longer than normal.

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 486.1 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 485.9 nm. What can we conclude?

A) The star is moving toward us.

B) The star is moving away from us.

C) The star is getting hotter.

D) The star is getting colder.

E) The "star" actually is a planet.

The star is moving toward us.

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 121.6 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 121.8 nm. What can we conclude?

A) The star is moving toward us.

B) The star is moving away from us.

C) The star is getting hotter.

D) The star is getting colder.

E) The "star" actually is a planet.

The star is moving away from us.

How does the spectrum of a molecule differ from the spectrum of an atom?

A molecule has additional spectral lines due to changes in its rotational and vibrational energies.

You observe a distant galaxy. You find that a spectral line normally found in the visible part of the spectrum is shifted toward the infrared. What do you conclude?

A) The galaxy is moving away from you.

B) The galaxy is moving toward you.

C) The galaxy has very weak gravity.

D) The galaxy is made purely of hydrogen.

E) The composition of the galaxy is changing.

The galaxy is moving away from you.

If one object has a large redshift and another object has a small redshift, what can we conclude about these two objects?

A) The one with the large redshift is moving toward us faster than the one with the small redshift.

B) The one with the large redshift is moving away from us, and the one with the small redshift is moving toward us.

C) The one with the large redshift is moving away from us faster than the one with the small redshift.

D) The one with the large redshift is hotter and theref

The one with the large redshift is moving away from us faster than the one with the small redshift.

If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet?

A) The planet is actually two bodies, one moving toward us, the other away from us.

B) The planet is in the process of falling apart.

C) The planet is in the process of formation.

D) The planet is rotating.

E) The planet's surface is very different from one side to the other.

The planet is rotating.

Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved. (Hint: Think about the laws of thermal radiation.)

A) The red star is more massive than the blue star.

B) The blue star is more massive than the red star.

C) The blue star is farther away than the red star.

D) The blue star has a hotter surface temperature than the red star.

E) The red star has a hotter surface temperature than the b

The blue star has a hotter surface temperature than the red star.

You observe the same spectral line in two stars that are identical in every way except that one rotates faster than the other. How does the spectral line differ between the two?

A) There is no difference.

B) The line in the faster rotating star is blueshifted.

C) The line in the faster rotating star is redshifted.

D) The line in the faster rotating star is broader.

E) The line in the faster rotating star is narrower.

The line in the faster rotating star is broader.

Which of the following statements about light focusing is not true?

A) In a healthy eye, light is focused on the retina.

B) Film should be placed at the focal plane in a camera.

C) If you try to look at an image that is not formed at the focal plane, it will be blurry.

D) The focal plane of a reflecting telescope is always located within a few inches of the primary mirror.

E) Light can be focused with a lens or a mirror

The focal plane of a reflecting telescope is always located within a few inches of the primary mirror.

Suppose the angular separation of two stars is smaller than the angular resolution of your eyes. How will the stars appear to your eyes?

A) You will not be able to see these two stars at all.

B) The two stars will look like a single point of light.

C) The two stars will appear to be touching, looking rather like a small dumbbell.

D) You will see two distinct stars.

E) You will see only the larger of the two stars, not the smaller one.

The two stars will look like a single point of light.

Which of the following is a principal advantage of CCDs over photographic film?

A) CCDs allow long exposures (e.g., minutes or hours), and film does not.

B) CCDs can record the colors of astronomical objects accurately, while film cannot.

C) CCDs capture a much higher percentage of the incoming photons than does film.

D) Images recorded with CCDs never require any image processing, while images recorded by film often do.

E) CCDs can be attached to modern telescopes more easily than cameras.

CCDs capture a much higher percentage of the incoming photons than does film.

Order the following in order of increasing efficiency of detecting photons of visible light.

A) eye, photographic film, CCD

B) photographic film, CCD, eye

C) CCD, eye, photographic film

D) CCD, photographic film, eye

E) eye, CCD, photographic film

eye, photographic film, CCD

Which of the following statements best describes the two principal advantages of telescopes over eyes?

A) Telescopes can collect far more light with far better angular resolution.

B) Telescopes can collect far more light with far greater magnification.

C) Telescopes have much more magnification and better angular resolution.

D) Telescopes collect more light and are unaffected by twinkling.

E) Telescopes can see farther without image distortion and can record more accurate colors.

Telescopes can collect far more light with far better angular resolution.

Currently, the largest optical telescope mirrors have a diameter of

A) 1 m.

B) 2 m.

C) 5 m.

D) 10 m.

E) 100 m.

10 m.

What do we mean by the diffraction limit of a telescope?

It is the best angular resolution the telescope could achieve with perfect optical quality and in the absence of atmospheric distortion.

Which of the following could not be measured by an observation that uses only imaging?

A) the rate at which a variable star brightens and dims

B) the general shape of an interstellar cloud of gas

C) the color of a planet

D) the brightness of a star in our sky

E) the number of bright stars in a nearby star cluster

the rate at which a variable star brightens and dims

Which of the following could not be determined by an observation that uses only spectroscopy?

A) the chemical composition of a distant star

B) the speed at which a distant galaxy is moving away from us

C) the surface temperature of a distant star

D) the rotation rate of a distant star

E) the size of a distant galaxy

the size of a distant galaxy

What is meant by spectral resolution?

It is a measure of how close two spectral lines can be distinguished.

Which of the following studies is best suited to a time monitoring experiment?

A) studying how different stars differ in their chemical compositions

B) studying whether a particular star's brightness is steady or variable

C) determining the age of the solar system

D) measuring the rotation rate of a distant star

E) estimating the time since the Big Bang

studying whether a particular star's brightness is steady or variable

Which of the following is always true about images captured with X-ray telescopes?

A) They are always very pretty.

B) They are always displayed with the highest possible angular resolution.

C) They are always useful for seeing through things.

D) They are always displayed in false color.

E) They are always displayed with north pointing upward in the images.

They are always displayed in false color.

What do astronomers mean by light pollution?

A) Light pollution refers to pollution caused by light industry as opposed to heavy industry.

B) Light pollution refers to harmful gases emitted by common street lights.

C) Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations.

D) Light pollution refers to the lights that must be used inside major observatories and that make it difficult for astronomers' eyes to adapt to darkness.

E

Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations.

What causes stars to twinkle?

A) It is intrinsic to the stars-their brightness varies as they expand and contract.

B) variations in the absorption of the atmosphere

C) variable absorption by interstellar gas along the line of sight to the star

D) bending of light rays by turbulent layers in the atmosphere

E) the inability of the human eye to see faint objects

bending of light rays by turbulent layers in the atmosphere

What is the purpose of adaptive optics?

A) to improve the angular resolution of telescopes in space

B) to eliminate the distorting effects of atmospheric turbulence for telescopes on the ground

C) to increase the collecting area of telescopes on the ground

D) to increase the magnification of telescopes on the ground

E) to allow several small telescopes to work together like a single larger telescope

to eliminate the distorting effects of atmospheric turbulence for telescopes on the ground

What is an artificial star?

A) a point of light in Earth's atmosphere created by a laser for the purpose of monitoring atmospheric fluctuations

B) a satellite orbiting Earth

C) a meteor

D) a possible source of dark matter in the universe

E) the unseen member of a binary star system

a point of light in Earth's atmosphere created by a laser for the purpose of monitoring atmospheric fluctuations

Which of the following is not a good reason to place observatories on remote mountain tops?

A) to reduce light pollution

B) to reduce light distortion

C) to reduce light absorption

D) to be able to observe at radio wavelengths

E) to be able to observe at infrared wavelengths

to be able to observe at radio wavelengths

Why do astronomers need different telescope designs to observe across the electromagnetic spectrum?

Photons of different energy behave differently and require different collection strategies.

Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes?

A) It is closer to the stars.

B) Stars do not twinkle when observed from space.

C) It can observe infrared and ultraviolet light, as well as visible light.

D) It never has to close because of bad weather.

E) Observers on the ground can use it at any time of day (i.e., not only during their night).

It is closer to the stars.

Which of the following wavelength regions cannot be studied with telescopes on the ground?

A) radio waves

B) ultraviolet

C) X rays

D) both B and C

E) both A and C

both B and C (ultraviolet, x-rays)

Telescopes operating at this wavelength must be cooled to observe faint astronomical objects.

A) radio

B) extreme infrared

C) visible

D) X-ray

E) gamma-ray

extreme infrared

At which wavelength range is there no current or planned space observatory?

A) radio

B) infrared

C) visible

D) X-ray

E) gamma-ray

radio

In what part of the electromagnetic spectrum do the biggest telescopes on Earth operate?

radio

What does the technique of interferometry allow?

A) It allows two or more telescopes to obtain a total light-collecting area much larger than the total light-collecting area of the individual telescopes.

B) It allows two or more telescopes to obtain the angular resolution of a single telescope much larger than any of the individual telescopes.

C) It allows us to determine the chemical composition of stars.

D) It allows astronomers to make astronomical observations without interference from l

It allows two or more telescopes to obtain the angular resolution of a single telescope much larger than any of the individual telescopes.

The largest effective telescope, created by radio interferometry, is the size of

A) several football fields, in a natural depression in Puerto Rico.

B) tens of miles across, in the deserts of New Mexico.

C) the state of New Mexico.

D) the continental United States.

E) Earth.

Earth.

In what wavelength range was interferometry first routinely used?

A) radio

B) infrared

C) optical

D) ultraviolet

E) X-ray

radio

What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter?

A) The flyby can use less expensive cameras than the orbiter.

B) The flyby is easier to design than the orbiter.

C) The fuel needed for an orbiter to slow down when it reaches Pluto is very expensive in and of itself.

D) The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft.

E) The question is incorrect; in general, orbiters are cheaper than flybys.

The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft.

What is aerobraking?

A) the technique of using a planetary atmosphere to change the orbit of a spacecraft

B) the use of a planetary atmosphere to redirect a spacecraft to another planet

C) the controlled landing of a spacecraft on a planetary surface

D) the gradual decrease of speed as a spacecraft leaves the solar system

E) the destruction of a spacecraft by the intense pressure as it descends into the atmosphere

the technique of using a planetary atmosphere to change the orbit of a spacecraft

What percentage of the mass of the solar nebula consisted of elements other than hydrogen and helium?

A) 0 percent

B) 0.1 percent

C) 2 percent

D) 20 percent

E) 80 percent

2 percent

Why did the solar nebula heat up as it collapsed?

A) Nuclear fusion occurring in the core of the protosun produced energy that heated the nebula.

B) As the cloud shrank, its gravitational potential energy was converted to kinetic energy and then into thermal energy.

C) Radiation from other nearby stars that had formed earlier heated the nebula.

D) The shock wave from a nearby supernova heated the gas.

E) Collisions among planetesimals generated friction and heat.

As the cloud shrank, its gravitational potential energy was converted to kinetic energy and then into thermal energy.

Where did the elements heavier than hydrogen and helium come from?

A) They were produced in the Big Bang.

B) They evolved from hydrogen and helium shortly after the Big Bang.

C) They were produced inside stars.

D) They were produced inside dense interstellar gas.

E) all of the above

They were produced inside stars.

Why did the solar nebula flatten into a disk?

A) The interstellar cloud from which the solar nebula formed was originally somewhat flat.

B) The force of gravity from the Sun pulled the material downward into a flat disk.

C) As the nebula cooled, the gas and dust settled onto a disk.

D) It flattened as a natural consequence of collisions between particles in the spinning nebula, changing random motions into more orderly ones.

E) The force of gravity from the planets pulled the material downw

It flattened as a natural consequence of collisions between particles in the spinning nebula, changing random motions into more orderly ones.

What happened during the accretion phase of the early solar system?

A) Atoms and molecules in the gas bonded together and solidified.

B) Particles grew by colliding and sticking together.

C) The solar nebula differentiated into metals inside of the frost line and ices beyond.

D) Large planetesimals captured atmospheres from the solar nebula.

E) Earth gained its oceans from icy planetesimal capture.

Particles grew by colliding and sticking together.

According to our theory of solar system formation, why do all the planets orbit the Sun in the same direction and in nearly the same plane?

A) The original solar nebula happened to be disk-shaped by chance.

B) Any planets that once orbited in the opposite direction or a different plane were ejected from the solar system.

C) The laws of conservation of energy and conservation of angular momentum ensure that any rotating, collapsing cloud will end up as a spinning disk.

D) The Sun formed first

The laws of conservation of energy and conservation of angular momentum ensure that any rotating, collapsing cloud will end up as a spinning disk.

Which of the following lists the ingredients of the solar nebula from highest to lowest percentage of mass of the nebula?

A) light gases (H, He), hydrogen compounds (H2O, CH4, NH3), rocks, metals

B) hydrogen compounds (H2O, CH4, NH3), light gases (H, He), rocks, metals

C) light gases (H, He), hydrogen compounds (H2O, CH4, NH3), metals, rocks

D) hydrogen compounds (H2O, CH4, NH3), light gases (H, He), metals, rocks

E) hydrogen compounds (H2O, CH4, NH3), rocks, metals, light gases (H, He)

light gases (H, He), hydrogen compounds (H2O, CH4, NH3), rocks, metals

What percentage of the solar nebula's mass consisted of hydrogen and helium gases?

A) 0.5 percent

B) 5 percent

C) 50 percent

D) 98 percent

E) 100 percent

98 percent

What percentage of the solar nebula's mass consisted of rocky material?

A) 0 percent

B) 0.4 percent

C) 2 percent

D) 20 percent

E) 80 percent

0.4 percent

What kind of material in the solar nebula could remain solid at temperatures as high as 1,500 K, such as existed in the inner regions of the nebula?

A) rocks

B) metals

C) silicon-based minerals

D) hydrogen compounds

E) molecules such as methane and ammonia

metals

What was the frost line of the solar system?

A) the distance from the Sun where temperatures were low enough for metals to condense, between the Sun and the present-day orbit of Mercury

B) the distance from the Sun where temperatures were low enough for rocks to condense, between the present-day orbits of Mercury and Venus

C) the distance from the Sun where temperatures were low enough for hydrogen compounds to condense into ices, between the present-day orbits of Mars and Jupiter

D) the dis

the distance from the Sun where temperatures were low enough for hydrogen compounds to condense into ices, between the present-day orbits of Mars and Jupiter

Why are the inner planets made of denser materials than the outer planets?

A) The Sun's gravity pulled denser materials toward the inner part of the solar nebula, while lighter gases escaped more easily.

B) Denser materials were heavier and sank to the center of the nebula.

C) In the inner part of the nebula only metals and rocks were able to condense because of the high temperatures, whereas hydrogen compounds, although more abundant, were only able to condense in the cooler outer regions.

In the inner part of the nebula only metals and rocks were able to condense because of the high temperatures, whereas hydrogen compounds, although more abundant, were only able to condense in the cooler outer regions.

Which of the following is the origin of almost all the large moons around the jovian planets?

A) They are captured asteroids.

B) They are captured comets.

C) They are captured planets.

D) They were formed by condensation and accretion in a disk of gas around the planet.

E) They were formed by giant impacts.

They were formed by condensation and accretion in a disk of gas around the planet.