chapter 7

The star Betelgeuse appears red; the star Rigel appears blue. What accounts for this difference? ​Betelgeuse and Rigel have different chemical compositions. ​Betelgeuse is moving away from Earth, Rigel is moving toward Earth. ​Betelgeuse is moving toward Earth, Rigel is moving away from Earth. ​The surface of Betelgeuse is hotter than the surface of Rigel. ​The surface of Betelgeuse is cooler than the surface of Rigel.

The surface of Betelgeuse is cooler than the surface of Rigel.

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 ​emission ​continuous ​Doppler ​ionization

absorption

If the photons from blackbody radiation pass through a cool gas, a(n) ____ spectrum is produced. absorption emission continuous Doppler ionization

absorption

​The _______________ is the amount of energy needed to pull an electron completely away from the nucleus. binding energy free energy

binding

An object that is a perfect absorber and emitter of radiation is called a(n) _______________. blackbody blue body red body

blackbody

The position of an absorption or emission line is useful in determining the ____. ​temperature of an object ​distance to an object ​chemical composition of an object ​motion of an object across the observer's line of sight ​motion of an object toward or away from the observer

chemical composition of an object

A spectrum that displays a smooth variation in intensity of all wavelengths without any breaks is a(n) ____ spectrum. ​absorption ​emission ​continuous ​Doppler ​ionization

continous

The amount of energy needed to move an electron from a lower energy level to a higher energy level is the ____. ​energy of the higher level ​energy of the lower level difference in energy between the two levels​ ​product of the energies of the two levels ​binding energy

difference in energy between the two levels​

The _______________ effect changes the observed wavelength of an emitted photon if the source is moving toward or away from the observer. Doppler ultrasound mri

doppler

​An atom must emit a photon when a(n) ____. ​electron moves from a lower to a higher energy level ​proton moves from a lower to a higher energy level ​proton moves from a higher to a lower energy level ​electron moves from a higher to a lower energy level ​atom becomes ionized

electron moves from a higher to a lower energy level

Emission lines are produced by ____. atoms that become ionized electrons that transfer from a high energy level to a low energy level electrons that transfer from a low energy level to a high energy level the intensity of agitation of atoms in a hot gas the motion of an object toward or away from the observer

electrons that transfer from a high energy level to a low energy level

​A spectrum that displays no energy except at very specific wavelengths where intense radiation is observed is a(n) ____ spectrum. ​absorption ​emission ​continuous ​Doppler ​ionization

emissiion

An atom that has gained one or more electrons is called an isotope. True False

false

Blackbody radiation only occurs in stars. True False

false

The Kelvin temperature scale is based on the freezing point of water. True False

false

The amount of energy needed to pull an electron completely away from the nucleus is called the Coulomb energy. True False

false

The lowest permitted energy level of an atom is called the neutral state. True False

false

​A continuous spectrum is created by a hot ionized gas. True False

false

​If absorption lines of sodium are not present in a star's spectrum, the star must not contain any sodium. True False

false

​Small differences in temperature between two stars produce small differences in the amount of energy they radiate. True False

false

A shift in the position of an emission line of an element toward the red or blue is produced by ____. ​atoms that become ionized ​electrons that transfer from a high energy level to a low energy level ​electrons that transfer from a low energy level to a high energy level ​the intensity of agitation of atoms in a hot gas ​the motion of an object toward or away from the observer

he motion of an object toward or away from the observer

According to Wien's Law, a(n) ____. hotter object will emit more short-wavelength (bluer) radiation hotter object will emit more long-wavelength (redder) radiation cooler object will produce fewer photons cooler object will produce more photons object will produce the same number of photons at different temperatures

hotter object will emit more short-wavelength (bluer) radiation

A(n) _______________ is an atom that has gained or lost one or more electrons. ion element molecule

ion

An atom that has lost or gained one or more electrons is called a(n) ____. ​ion ​isotope ​nucleus ​molecule ​electron

ion

If a neutral atom gains or loses an electron, it ___________. becomes an isotope is at absolute zero is excited is ionized is in the ground state

is ionized

An atom can only have orbits of certain sizes, called _______________ orbits. permitted restricted

permitted

An object moving away from the observer will exhibit a(n) _______________ shift due to the Doppler effect. red blue green

red

Using Wien's law, you can measure the ____ of a distant object without having to travel to it. ​binding energy ​temperature ​radial motion ​energy output ​atomic composition

temp

Blackbody radiation is caused by an object's ____. ​chemical structure ​binding energy ​excitation level ​absolute zero ​thermal agitation

thermal agitation

Atoms are mostly empty space. True False

treu

A hot object that is glowing orange will become redder as it cools. True False

true

An absorption spectrum is created when blackbody radiation passes through a cool gas. True False

true

The number of protons in the nucleus determines which element it is. True False

true

​If you move an electron from the ground state to a higher energy level, the atom becomes an excited atom. True False

true

​In blackbody radiation, short-wavelength and long-wavelength photons are rare. True False

true

​The agitation of atoms in a hot body creates a continuous spectrum of radiation.

true

​Most of the mass of an atom is ____. ​in the electron cloud ​spread evenly through the atom ​made up of electrons ​concentrated in the nucleus ​concentrated in a disk around the nucleus

​concentrated in the nucleus

The Stefan-Boltzmann law relates the ____. ​energy emitted from a surface every second to the temperature of the surface ​wavelength of peak intensity to the Kelvin temperature ​binding energy to the Coulomb force ​difference in energy level to the wavelength of the emitted photon ​observed wavelength to the velocity of the object

​energy emitted from a surface every second to the temperature of the surface

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 ​if they match one of several possible wavelengths that are absorbed by all elements ​if they match the only particular wavelength that can be absorbed by that element ​if they match the only particular wavelength that can be absorbed by all elements ​no matter what wavelength they have

​if they match one of several possible wavelengths that are absorbed by that element

The arrangement of permitted orbits is ____. ​the same for each neutron ​unique for each electron ​the same for all elements ​the same for all molecules ​unique for each element

​unique for each element

​Electromagnetic waves are generated whenever the ____. ​motion of any particle is changed ​motion of any charged particle changes ​motion of a positively charged particle is changed ​motion of a negatively charged particle is changed ​acceleration of any charged particle is changed

motion of any charged particle changes

As a blackbody becomes hotter it will radiate ____. ​less energy, at a longer wavelength of maximum intensity ​less energy, at a shorter wavelength of maximum intensity ​more energy, at a longer wavelength of maximum intensity ​more energy, at a shorter wavelength of maximum intensity ​more energy, at a constant wavelength of maximum intensity

​more energy, at a shorter wavelength of maximum intensity

The Doppler effect is useful in measuring the ____. ​distance to an object ​chemical composition of an object ​temperature of an object ​motion of an object across the line of sight of an observer ​motion of an object toward or away from the observer

​motion of an object toward or away from the observer

​The binding energy is the amount of energy ____. ​needed to pull a proton completely away from the nucleus ​needed to pull an electron completely away from the nucleus ​needed to push a neutron into the nucleus ​needed to completely separate all particles in the atom ​necessary to move a proton to a permitted orbit

​needed to pull an electron completely away from the nucleus

The wavelength of maximum intensity is useful in measuring the ____. ​surface temperatures of an object from their colors ​distance to an object from their colors ​chemical composition of an object ​motion of an object across the observer's line of sight ​motion of an object toward or away from the observer

​surface temperatures of an object from their colors

​The type of elements present in a gas can be determined by studying the ____. ​number of ionized atoms in the gas ​energy of the electrons being emitted by the gas ​number of photons being absorbed or emitted by the gas ​wavelengths of photons absorbed or emitted from the gas ​number of excited atoms in the gas

​wavelengths of photons absorbed or emitted from the gas​wavelengths of photons absorbed or emitted from the gas