Chapter 7/8 Flashcards
Atoms are mostly empty space.
True
An atom that has gained one or more electrons is called an isotope
false
The number of protons in the nucleus determines which element it is.
true
The amount of energy needed to pull an electron completely away from the nucleus is called the
Coulomb energy
false
The lowest permitted energy level of an atom is called the neutral state
false
A certain type of atom can only absorb certain wavelengths.
true
If you move an electron from the ground state to a higher energy level, the atom becomes an excited
atom
true
The Kelvin temperature scale is based on the freezing point of water
false
A hot object that is glowing orange will become redder as it cools.
true
in blackbody radiation, short-wavelength and long-wavelength photons are rare.
true
Small differences in temperature between two stars produce small differences in the amount of energy they radiate
false
If absorption lines of sodium are not present in a star’s spectrum, the star must not contain any sodium
false
A continuous spectrum is created by a hot ionized gas
false
An absorption spectrum is created when blackbody radiation is passes through a cool gas
true
The agitation of atoms in a hot body creates a continuous spectrum of radiation
true
An atom that has lost or gained one or more electrons is called a(n)
ion
A neutral atom must have ____
An equal number of protons and electrons
Most of the mass of an atom is
Concentrated in the Nucleus
The particle in an atom that carries a negative charge is the
Electron
The binding energy is the amount of energy
needed to pull an electron completely away from the Atom
The arrangement of permitted orbits is
Unique for each element
The type of element is determined by the number of
Protons in the atom
Atoms that have the same number of protons but different number of neutrons are called
isotopes
An atom must emit a photon when a
Electon moves from a higher to a lower energy level
The amount of energy needed to move an electron from a lower energy level to a higher energy level is
the ____.
Difference in energy between two levels
Photons of light can be absorbed by an atom of an element ____.
if they match one of several possible wavelengths that are absorbed by that element
The type of elements present in a gas can be determined by studying the ___
wavelengths of photons absorbed or emitted from the gas
Blackbody radiation is caused by an object’s ___
temperature
As a blackbody becomes hotter it will radiate ____.
more energy, at a shorter wavelength of maximum intensit
An object that acts as a blackbody emits photons because ____
atoms in the object collide, changing the motion of charged particle
According to Wien’s Law, a(n) ____
hotter object will emit more short wavelength (bluer) radiation
Using Wien’s law, you can measure the ____ of a distant object without having to travel to it
temperature
The star Betelgeuse appears red; the star Rigel appears blue. What accounts for this difference
It’s cooler on betelgeuse
If the photons from blackbody radiator radiation pass through a cool gas, a(n) ____ spectrum is
produced
absorption
The photons coming from blackbody radiation create a(n) ____ spectrum
continuous
The photons coming from an excited gas create a(n) ____ spectrum
emission
A spectrum that displays a smooth variation in intensity of all wavelengths without any breaks is a(n
continuous
A spectrum that displays a smooth variation in intensity over a range of wavelengths with breaks
where no energy is observed at specific wavelengths is a(n) ____ spectrum
absorption
A spectrum that displays no energy except at very specific wavelengths where intense radiation is
observed is a(n) ____ spectrum
emission
star like the Sun emits a(n) ____ spectrum
absorption
The Doppler effect is useful in measuring the ____
motion of an object toward or away from the observer
The wavelength of maximum intensity is useful in measuring the __
surface temp.
The position of an absorption or emission line is useful in determining the ____
chemical composition of an object
Emission lines are produced by ____.
electrons that transfer from a high energy level to a low energy level
Absorption lines are produced by ____
Electrons that transfer from a low energy level to high energy level
A continuous spectrum is produced by ___
the intensity of agitation of atoms in a hot gas
A shift in the position of an emission line of an element toward the red or blue is produced by ___
the motion of an object toward or away from the observe
The _______________ is the amount of energy needed to pull an electron completely away from the
nucleus
Ionization energy
A(n) _______________ is an atom that has gained or lost one or more electrons.
ion
An atom can only have orbits of certain sizes, called _______________ orbits.
Permitted orbits
Physicists and astronomers usually refer to the permitted orbits of an atom as the atom’s
_______________ levels
energy
The _______________ temperature scale is used in astronomy because it is based on absolute zero.
kelvin
An object that is a perfect absorber and emitter of radiation is called a(n) _______________.
blackbody
The _______________ effect changes the observed wavelength of an emitted photon if the source is
moving toward or away from the observer
doppler effect
A(n) _______________ spectrum is produced by a hot, excited gas.
emission
A hot blackbody emits a(n) _______________ spectrum
continuous
An object moving away from the observer will exhibit a(n) _______________ shift due to the Doppler
effect
redshift
The visible surface of the Sun is composed of solid matter.
false
Granulation is caused by convection currents just below the photosphere
true
The layer above the chromosphere is the photosphere
true
The upper chromosphere is hot enough to emit X-rays
true
The corona is so dim that it is not visible in Earth’s daytime sky
true
Almost all the light we receive from the Sun escapes from underneath its photosphere
false
Sunspot numbers follow a seven-year cycle
false
Sunspots are parts of active solar regions dominated by magnetic fields that encompass all layers of
the Sun’s atmosphere
false
Helioseismology maps of rotation in the Sun’s interior show that its internal gases rotate with equal
periods
false
Sunspots tend to occur in groups, or pairs, with the magnetic field around the pair resembling that
around a bar magnet
true
Spicules can trigger communications blackouts and auroras on Earth
false
The Sun is a ball of hot gas held together by its own gravity
true
Nuclear fusion in the Sun is tremendously powerful
false
What is the average distance between the Sun and Earth?
1 au
. What is the approximate average temperature of the Sun’s surface
. 5800o
C
Which is the correct order of the Sun’s atmospheric layers, from the innermost to outermost
Photosphere, the Chromosphere, the Transition Region and the Corona.
Which two elements are most abundant within the Sun?
hydrogen and helium
What are the dark regions that give the Sun’s photosphere a mottled appearance
granules
What causes granulation on the photosphere?
convection
Granulation is evidence that energy in the photosphere ____.
is flowing upward
The pink color of the chromosphere is produced by the combined light of three emission lines of
hydrogen: ____.
red, blue, violet
Of the following parts of the Sun, which is the hottest
coronona
Astronomers often record solar images in the ____ part of the electromagnetic spectrum because the
gaseous layers high in the Sun’s atmosphere are very hot and emit most of their light at short wavelengths.
ultraviolet
Why does the temperature of the corona rise with latitude?
Atoms within the corona become more ionized at higher altitudes
the corona can reach temperatures of up to
2,000,000
What methodology do astronomers use to map the inside of the Sun
helioseismology
When mapping the interior of the Sun, astronomers must measure _____ as the photosphere moves up
and down
doppler shifts
When mapping the interior of the Sun, astronomers must measure _____ as the photosphere moves up
and down
doppler shifts
Galileo proposed that the Sun is a rotating sphere after he
b. observed sunspots move across the surface of the Sun
Astronomers refer to the dark center of a sunspot as a(n) _
umbra
Astronomers can measure the magnetic fields of sunspots using the ____, which splits spectral lines
into multiple components.
zeeman effect
Consider the complete magnetic cycle of sunspot activity on the Sun. Approximately how many years
is this cycle
11 year
The Babcock model of the solar magnetic cycle explains the sunspot cycle as primarily a consequence
of the Sun’s ___
differential rotation
When two arches in a magnetic field encounter each other, ____ can cause powerful eruptions called
____.
reconnection events; flares
What occurs on the surface of the Sun during a solar cycle minimum?
little to no sunspot activity
The _____ occurs when some of the energy in the convective motion of gas is converted into magnetic
field energy.
reconnection event
How many nuclear reactions occur in a proton-proton chain
two
Which of the natural forces bind atomic nuclei
strong force
During the first reaction of the proton-proton chain of nuclear fusion, a weak force causes one of the
protons to transform into a neutron and emit ____
. a positron and a neutrino
What is released from the proton-proton chain and is immediately absorbed by the surrounding gas,
thereby heating it
neutrinos
In order for nuclear fusion to occur, atomic nuclei must overcome the ____ by colliding violently
Coulomb barrier
Why was the Davis experiment only able to detect one-third of the neutrinos originally predicted
The other two-thirds of neutrinos dissipated while traveling to Earth.
