Question 1

The majority of the naturally occurring elements in the periodic table that decay radioactively are:

Accepted Answer

A) arranged randomly throughout the table, because stability is largely independent of nuclear mass. 
B) at the low-mass end of the table, since the nuclear mass is too small to maintain stability. 
C) in the center of the table. 
D) at the high-mass end of the table, since the large atomic nuclei are unstable. 
A) arranged randomly throughout the table, because stability is largely independent of nuclear mass. 
B) at the low-mass end of the table, since the nuclear mass is too small to maintain stability. 
C) in the center of the table. 
D) at the high-mass end of the table, since the large atomic nuclei are unstable.

Question 2

At absolute zero temperature, which of the following conditions holds?

Accepted Answer

A) Electrons stop moving around the nuclei of atoms. 
B) The motion of atoms ceases. 
C) Electrons in all atoms move to their ground states. 
D) The motion of atoms becomes the minimum possible (but not zero). 
A) Electrons stop moving around the nuclei of atoms. 
B) The motion of atoms ceases. 
C) Electrons in all atoms move to their ground states. 
D) The motion of atoms becomes the minimum possible (but not zero).

Question 3

You are asked to design a detection system for human beings (or animals) in darkness, using infrared detection. If human beings are at a temperature of about 310 K, what would need to be the wavelength of peak sensitivity of your equipment or cameras (1 μm = 10-6 m)? (Hint: Use Wien's law.)

Accepted Answer

A) 9.35 μm 
B) 0.935 μm 
C) 0.00094 μm or 0.94 nm 
D) 90 μm 
A) 9.35 μm 
B) 0.935 μm 
C) 0.00094 μm or 0.94 nm 
D) 90 μm

Question 4

The Stefan-Boltzmann law relating energy per unit area F emitted by an object to its temperature T, F = σT 4, is obeyed ideally by what type of object?

Accepted Answer

A) only hot gases, whose atoms emit and absorb only specific colors (e.g., neon tubes) 
B) all objects, whatever their color or reflective properties 
C) a red-colored object that absorbs blue light but reflects red light 
D) a blackbody, a perfect absorber and emitter of energy at all wavelengths 
A) only hot gases, whose atoms emit and absorb only specific colors (e.g., neon tubes) 
B) all objects, whatever their color or reflective properties 
C) a red-colored object that absorbs blue light but reflects red light 
D) a blackbody, a perfect absorber and emitter of energy at all wavelengths

Question 5

How is a star's spectrum changed when looking at the absorption spectrum from an approaching star as compared to if the star were stationary?

Accepted Answer

A) All the absorption lines would shift, uniformly, toward the long wavelength end of the spectrum. 
B) All the absorption lines would shift, uniformly, toward the short wavelength end of the spectrum. 
C) All the absorption lines would shift toward the long wavelength end of the spectrum, each line shifting by an amount proportional to its wavelength. 
D) All the absorption lines would shift toward the short wavelength end of the spectrum, each line shifting by an amount proportional to its wavelength. 
A) All the absorption lines would shift, uniformly, toward the long wavelength end of the spectrum. 
B) All the absorption lines would shift, uniformly, toward the short wavelength end of the spectrum. 
C) All the absorption lines would shift toward the long wavelength end of the spectrum, each line shifting by an amount proportional to its wavelength. 
D) All the absorption lines would shift toward the short wavelength end of the spectrum, each line shifting by an amount proportional to its wavelength.

Question 6

The speed of light:

Accepted Answer

A) was first accurately determined by Galileo in an experiment involving lanterns and shutters. 
B) can be determined by observing the motions of the moons of Jupiter. 
C) was not determined until the advent of lasers in 1960. 
D) is too high to measure and consequently is still unknown. 
A) was first accurately determined by Galileo in an experiment involving lanterns and shutters. 
B) can be determined by observing the motions of the moons of Jupiter. 
C) was not determined until the advent of lasers in 1960. 
D) is too high to measure and consequently is still unknown.

Question 7

When a solid body is heated to a temperature T, the total radiated energy flux F from this body per second per unit area is given by (where σ is a constant):

Accepted Answer

A) F = σT. 
B) F = σ/T 2. 
C) F = σT 4. 
D) FT = σ. 
A) F = σT. 
B) F = σ/T 2. 
C) F = σT 4. 
D) FT = σ.

Question 8

The diameter of your finger is 1 or 2 cm. What type of electromagnetic wave has a wavelength this size?

Accepted Answer

A) ultraviolet 
B) visible 
C) microwave 
D) radio 
A) ultraviolet 
B) visible 
C) microwave 
D) radio

Question 9

The temperature of hydrogen gas is such that electrons are excited by atomic collisions up to the n = 3 atomic energy levels. Emission lines from which spectral sequences result when electrons return to the ground state?

Accepted Answer

A) Paschen (IR), Balmer (visible), and Lyman (UV) series 
B) Lyman (UV) series only 
C) Balmer (visible) and Lyman (UV) series 
D) Balmer (visible) series only 
A) Paschen (IR), Balmer (visible), and Lyman (UV) series 
B) Lyman (UV) series only 
C) Balmer (visible) and Lyman (UV) series 
D) Balmer (visible) series only

Question 10

To what physical parameter is the temperature of a thin gas most closely related?

Accepted Answer

A) average number of collisions per second between molecules 
B) pressure of the gas 
C) average speed of the molecules 
D) mean mass per unit volume, or density, of the gas 
A) average number of collisions per second between molecules 
B) pressure of the gas 
C) average speed of the molecules 
D) mean mass per unit volume, or density, of the gas

Question 11

Compare the spectrum emitted from a blackbody at 12,000 K and at 3000 K, using Figure 5-12 of Universe, 11th ed. Where in the spectrum does the object emit more radiation when it is cooler than when it is warmer?
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Accepted Answer

A) ultraviolet 
B) visible 
C) infrared 
D) nowhere 
A) ultraviolet 
B) visible 
C) infrared 
D) nowhere

The majority of the naturally occurring elements in the periodic table that decay radioactively are:

At absolute zero temperature, which of the following conditions holds?

You are asked to design a detection system for human beings (or animals) in darkness, using infrared detection. If human beings are at a temperature of about 310 K, what would need to be the wavelength of peak sensitivity of your equipment or cameras (1 μm = 10^-6 m)? (Hint: Use Wien's law.)

The Stefan-Boltzmann law relating energy per unit area F emitted by an object to its temperature T, F = σT ⁴, is obeyed ideally by what type of object?

How is a star's spectrum changed when looking at the absorption spectrum from an approaching star as compared to if the star were stationary?

The speed of light:

When a solid body is heated to a temperature T, the total radiated energy flux F from this body per second per unit area is given by (where σ is a constant):

The diameter of your finger is 1 or 2 cm. What type of electromagnetic wave has a wavelength this size?

The temperature of hydrogen gas is such that electrons are excited by atomic collisions up to the n = 3 atomic energy levels. Emission lines from which spectral sequences result when electrons return to the ground state?

To what physical parameter is the temperature of a thin gas most closely related?

Compare the spectrum emitted from a blackbody at 12,000 K and at 3000 K, using Figure 5-12 of Universe, 11th ed. Where in the spectrum does the object emit more radiation when it is cooler than when it is warmer?

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

Optics and Telescopes

Comparative Planetology I: Our Solar System

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Mercury, Venus, and Mars: Terrestrial, yet Unique

Jupiter and Saturn: Lords of the Planets

Jupiter and Saturns Satellites of Fire and Ice

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Cosmology: The Origin and Evolution of the Universe

Exploring the Early Universe

The Search for Extraterrestrial Life

Filters

Exam 5: The Nature of Light

The majority of the naturally occurring elements in the periodic table that decay radioactively are:

At absolute zero temperature, which of the following conditions holds?

You are asked to design a detection system for human beings (or animals) in darkness, using infrared detection. If human beings are at a temperature of about 310 K, what would need to be the wavelength of peak sensitivity of your equipment or cameras (1 μm = 10-6 m)? (Hint: Use Wien's law.)

The Stefan-Boltzmann law relating energy per unit area F emitted by an object to its temperature T, F = σT 4, is obeyed ideally by what type of object?

How is a star's spectrum changed when looking at the absorption spectrum from an approaching star as compared to if the star were stationary?

The speed of light:

When a solid body is heated to a temperature T, the total radiated energy flux F from this body per second per unit area is given by (where σ is a constant):

The diameter of your finger is 1 or 2 cm. What type of electromagnetic wave has a wavelength this size?

The temperature of hydrogen gas is such that electrons are excited by atomic collisions up to the n = 3 atomic energy levels. Emission lines from which spectral sequences result when electrons return to the ground state?

To what physical parameter is the temperature of a thin gas most closely related?

Compare the spectrum emitted from a blackbody at 12,000 K and at 3000 K, using Figure 5-12 of Universe, 11th ed. Where in the spectrum does the object emit more radiation when it is cooler than when it is warmer? ​ ​

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

Optics and Telescopes

Comparative Planetology I: Our Solar System

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Mercury, Venus, and Mars: Terrestrial, yet Unique

Jupiter and Saturn: Lords of the Planets

Jupiter and Saturns Satellites of Fire and Ice

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Cosmology: The Origin and Evolution of the Universe

Exploring the Early Universe

The Search for Extraterrestrial Life

Filters

You are asked to design a detection system for human beings (or animals) in darkness, using infrared detection. If human beings are at a temperature of about 310 K, what would need to be the wavelength of peak sensitivity of your equipment or cameras (1 μm = 10^-6 m)? (Hint: Use Wien's law.)

The Stefan-Boltzmann law relating energy per unit area F emitted by an object to its temperature T, F = σT ⁴, is obeyed ideally by what type of object?

Compare the spectrum emitted from a blackbody at 12,000 K and at 3000 K, using Figure 5-12 of Universe, 11th ed. Where in the spectrum does the object emit more radiation when it is cooler than when it is warmer?