Deck 4: Spectroscopy: The Inner Workings of Atoms

Question 1

The radial velocity of a star's motion in space can also broaden its spectral lines.

Answer 1

False

Question 2

An X-ray photon has more energy than a visible photon.

Answer 2

True

Question 3

The absorption lines for a cool thin gas are identical in color and energy to the emission lines of the same gas if hot enough to glow.

Answer 3

True

Question 4

The red hydrogen alpha line carries more energy per photon than the blue-green hydrogen beta line does.

Question 5

In the Bohr model,the transitions of electrons down to ground state produce the Lyman lines in the ultraviolet.

Question 6

Molecular spectra,like elemental ones,involve only the vibration of the particles.

Question 7

If a fire truck's siren is rising in pitch,it must be approaching us.

Question 8

A cool,thin gas produces absorption lines.

Question 9

The Doppler effect can reveal the rotation speed of a star by the splitting of the spectral lines.

Question 10

Spectroscopy of a star can reveal its temperature,composition,and line-of-sight motion.

Question 11

A low-density,hot gas produces a continuous spectrum.

Question 12

Only a hot,thin gas can produce an emission line.

Question 13

The larger the redshift,the faster the distant galaxy is rushing toward us.

Question 14

The spectral lines of each element are distinctive to that element,whether we are looking at emission or absorption lines.

Question 15

The shorter a wave's wavelength,the greater its energy.

Question 16

A low density gas must be hot in order to produce an absorption line.

Question 17

The Balmer lines of hydrogen involve electron transitions from the ground state to higher levels.

Question 18

All wavelengths of light travel at the same speed in a vacuum,and carry the same energy per photon.

Question 19

In an atom,electrons can have only specific,allowed orbital energies.

Question 20

The Zeeman effect reveals the presence of strong magnetic fields by the splitting of spectral lines.

Question 21

The line intensity of a spectrum depends both on the abundance of a particular element and its temperature as well.

Question 22

The three laws dealing with the creation of various spectra are due to:

A) Newton.
B) Fraunhofer.
C) Kirchhoff.
D) Bohr.
E) Einstein.

Question 23

The particles which enter into chemical reactions are the atom's:

A) protons.
B) neutrons.
C) positrons.
D) electrons.
E) mesons.

Question 24

What is spectroscopy?

A) an analysis of the way in which atoms absorb and emit light
B) a study of the geometry of rainbows
C) an observational technique to measure the brightness of light at different colors
D) the use of CCDs to capture light more efficiently than with photographic film
E) a method to freeze atmospheric turbulence for better resolution

Question 25

Typical stellar spectra appear as:

A) a series of bright, colored lines.
B) an unbroken rainbow of colors.
C) a rainbow, but with some dark lines mixed in.
D) a rainbow with some bright lines on top of the continuum.
E) a very redshifted rainbow due to the expansion of the universe.

Question 26

An emission spectrum can be used to identify a(n):

A) proton.
B) electron.
C) neutron.
D) atom.
E) neutrino.

Question 27

The classical model of the hydrogen atom that explains its spectral line structure is due to:

A) Kirchhoff.
B) Bohr.
C) Fraunhofer.
D) Newton.
E) Mendeleev.

Question 28

The Orion Nebula,M-42,is a hot,thin cloud of glowing gas,so its spectrum is:

A) a continuum, strongest in the color red.
B) a few bright lines against a dark background.
C) a few dark lines in the continuum.
D) a continuum, but with both bright and dark lines mixed in.
E) not in the visible portion of the spectrum.

Question 29

A hydrogen atom consists of an electron and a(n):

A) proton.
B) ion.
C) neutrino.
D) neutron.
E) lepton.

Question 30

The particle which adds mass but no charge to the atomic nucleus is the:

A) positron.
B) proton.
C) neutron.
D) neutrino.
E) alpha particle.

Question 31

An incandescent light (glowing tungsten filament)produces:

A) a continuous spectrum, with the peak giving the temperature of the filament.
B) an emission spectrum, with bright lines due to ionized tungsten.
C) an absorption spectrum, with dark lines due to the solid filament.
D) a continuum, with bright tungsten lines added.
E) a continuum, with dark lines of tungsten and argon as well.

Question 32

The broader the spectral line,the higher the pressure of the gas that is creating it.

Question 33

In the atom,which particles give the element its identity (atomic number)?

A) positrons
B) electrons
C) protons
D) neutrons
E) neutrinos

Question 34

The element first found in the Sun's spectrum,then on Earth 30 years later,is:

A) hydrogen.
B) helium.
C) solarium.
D) technetium.
E) aluminum.

Question 35

Which of the following type of electromagnetic radiation has the highest energy?

A) radio
B) infrared
C) visible
D) ultraviolet
E) X-ray

Question 36

In our Sun,the spectral lines of hydrogen are weak,compared to their appearance in hotter stars.

Question 37

Which of the following type of electromagnetic radiation has the lowest energy?

A) radio
B) infrared
C) visible
D) ultraviolet
E) X-ray

Question 38

The Fraunhofer lines in the solar spectrum are actually:

A) emission lines from hot gases in the chromosphere of the Sun.
B) emission sections of the continuous spectrum of the photosphere.
C) Zeeman lines around sunspots due to their strong magnetic fields.
D) absorption lines due to the thin outer layer above the photosphere.
E) redshifted lines due to the Sun's rotation.

Question 39

A neon light (thin hot neon gas in a sealed tube)gives us:

A) a continuous spectrum, since the neon is hot enough to glow.
B) a few bright emission lines, telling us the gas is neon.
C) a continuum, with dark lines identifying the neon atoms that are present.
D) a lot of random bright red lines due to the motion of the hot atoms.
E) nothing visible to us, but a lot of infrared lines as heat.

Question 40

Which of these is the classic continuous spectrum?

A) sunlight
B) a rainbow
C) a neon light
D) a fluorescent light
E) a glowing nebula, such as M-42

Question 41

The broadening of spectral lines can be caused by:

A) density of the hot medium.
B) thermal motion of the hot atoms.
C) rotation of the star.
D) magnetic fields of the star.
E) All of the above

Question 42

In Bohr's model of the atom,electrons:

A) only make transitions between orbitals of specific energies.
B) are not confined to specific orbits.
C) are spread uniformly through a large, positive mass.
D) can be halfway between orbits.
E) move from orbit to orbit in many small steps.

Question 43

The energy required to ionize a hydrogen atom whose electron is in the ground state (energy level 1)is:

A) 10.2 eV.
B) 12.1 eV.
C) 12.75 eV.
D) 13.1 eV.
E) 13.6 eV.

Question 44

Why are molecular lines more complex than elemental spectral lines?

A) Molecules have two or more atoms.
B) Molecules can vibrate and rotate as well.
C) Molecules are heavier than atoms.
D) Molecules are the basis of life.
E) Most of the universe is made of molecules, not individual atoms.

Question 45

According to the Zeeman effect,the splitting of a sunspot's spectral lines is due to:

A) their rapid rotation.
B) temperature variations.
C) their magnetic fields.
D) their radial velocity.
E) a Doppler shift.

Question 46

If a source of light is approaching us at 3,000 km/sec,then all its waves are:

A) blue shifted by 1%.
B) redshifted by 1%.
C) not affected, as c is constant regardless of the direction of motion.
D) blue shifted out of the visible spectrum into the ultraviolet.
E) redshifted out of the visible into the infrared.

Question 47

Since the difference in energy between the different rotational states in a molecule is very small,many molecular lines can be observed with:

A) visible light spectrometers.
B) radio or microwave telescopes.
C) high energy observatories like Chandra, in orbit above our atmosphere.
D) ultraviolet balloons flying above the ozone layer.
E) infrared telescopes on mountaintops.

Question 48

According to the photoelectric effect in order to release electrons from a solid,the light incident upon it must:

A) have a high intensity.
B) have a low intensity.
C) have a long wavelength.
D) have a short wavelength.
E) None of the above.

Question 49

The splitting of spectral lines in the presence of strong magnetic fields is the:

A) Doppler effect.
B) Second Law of Kirchhoff.
C) Zeeman effect.
D) photoelectric effect.
E) polarization of sunlight.

Question 50

The energy required to move an electron in a hydrogen atom from energy level 2 to energy level 3 is:

A) 0.7 eV.
B) 1.9 eV.
C) 2.6 eV.
D) 2.9 eV.
E) 3.4 eV.

Question 51

Spectral lines are often referred to as the stars' "fingerprints" because:

A) fingerprints also consist of individual lines that make a pattern.
B) both are unique to their source.
C) both can be easily categorized.
D) both are characteristic of the individual that produced them.
E) All of these are correct.

Question 52

A heavy neutral atom,such as iron,produces many spectral lines compared to light elements like hydrogen and helium.Why?

A) Because of the larger number of electrons and corresponding energy levels, more transitions are possible.
B) Because of the larger number of electrons, there are many ionization levels possible.
C) Because of the larger number protons, the amount of force holding the electrons to the atom can vary between different iron atoms.
D) Because of the atom's larger size, it will be hit by more photons in a beam of light.

Question 53

The Balmer Beta absorption line is a result of a transition of an electron in a hydrogen atom from:

A) level 2 to level 3.
B) level 2 to level 4.
C) level 3 to level 2.
D) level 4 to level 2.
E) None of the above.

Question 54

The energy required to move an electron in a hydrogen atom from energy level 1 to energy level 2 is:

A) 10.2 eV.
B) 12.1 eV.
C) 12.75 eV.
D) 13.1 eV.
E) 13.6 eV.

Question 55

For hydrogen,the transition from the second to the fourth energy level produces:

A) a red emission line.
B) a blue green absorption line.
C) a violet emission line.
D) an infrared emission line.
E) an ultraviolet absorption line.

Question 56

The observed spectral lines of a star are all shifted towards the red end of the spectrum.Which statement is true?

A) This is an example of the photoelectric effect.
B) This is an example of the Doppler effect.
C) The second law of Kirchhoff explains this.
D) The star is not rotating.
E) The star has a radial velocity towards us.

Question 57

In space,positive ions are the result of:

A) protons escaping from the nuclei of atoms at tremendous temperatures.
B) electrons being stripped off the outer electron shell for hot atoms.
C) positrons being added to the atomic nucleus at great energies.
D) positrons being added to the electron clouds, destroying the electrons.
E) electrons being added to the cloud, giving them a surplus over protons.

Question 58

To have a negative ion,you must have:

A) taken away a proton from the nucleus.
B) added a positron to the nucleus.
C) added a positron to the outer electron shell.
D) added an electron to the outer electron shell.
E) None of these; only positive ions can exist in nature.

Question 59

In a hydrogen atom,a transition from the third to the second energy level will produce:

A) a red emission line.
B) a blue green absorption line.
C) a violet emission line.
D) an infrared emission line.
E) an ultraviolet absorption line.

Question 60

Emission lines of hydrogen that are found in the ultraviolet part of the electromagnetic spectrum are formed by electrons transitioning from:

A) any level to level 2.
B) level 2 to any level.
C) any level to level 1.
D) level 1 to any level.
E) any level to level 3.

Question 61

State the relationship between photon energy,frequency,and wavelength.

Question 62

A(n)________ spectrum is created by a glowing,hot thin gas,such as M-42 in Orion.

Question 63

The spectra of molecules are more complex because molecules can vibrate and ________ instead of just exhibiting electronic transitions like atoms.

Question 64

The ________ explains why the spectral lines from a rapidly rotating star are broader than those from a slowly rotating star.

Question 65

The ________ spitting of the spectral lines is due to a strong magnetic field present.

Question 66

Explain what types of information can be obtained from a spectral line.

Question 67

The colors of a neon light arise because it is a(n)________ spectrum.

Question 68

The longer the wavelength of the photon,the ________ the energy it carries.

Question 69

The Great Nebula in Orion,M-42,is a low-density cloud of hot gas.Use Kirchhoff's laws to describe its spectrum.

Question 70

If we increased the pressure in the gas of a blackbody,how will the spectral lines be affected?

Question 71

The emission line for a given atom shows spectral features at the ________ location as in its absorption spectrum.

Question 72

If the rest wavelength of a certain line is 600 nm,but we observe it at 594 nm,then:

A) the source is approaching us at 1 % of the speed of light.
B) the source is approaching us at 0.1 % of the speed of light.
C) the source is receding from us at 10% of the speed of light.
D) the source is getting 1% hotter as we watch.
E) the source is spinning very rapidly, at 1% of the speed of light.

Question 73

According to Kirchhoff's first law why do dense,hot bodies create the type of spectrum they do?

Question 74

________ is the process of stripping electrons from their atoms.

Question 75

________ is the scientific study of the distribution of electromagnetic waves by energy and how these patterns are created in atoms and molecules.

Question 76

Explain how Bohr's model creates emission and absorption lines in the spectrum.

Question 77

What information about a star can be inferred from its Doppler shift?

Question 78

Because the changes in energy levels happen in discrete steps,we refer to these as ________ leaps.

Question 79

What information about an astronomical object can be determined by observing its spectrum?

A) its temperature
B) its radial motion
C) its chemical composition
D) whether it has a strong magnetic field
E) All of the above

Question 80

All Lyman emission lines are transitions from the excited state to ________ state.