Physic 20 CH 26-34
Which of the following isotopes is radioactive?
Carbon-14
The ratio of a photon's energy to its frequency is
Planck's constant
It's impossible for a hydrogen atom to emit an alpha particle
True
Which of these electromagnetic waves has the shortest wavelength?
X-rays
An element will decay to an element with higher atomic number in the periodic table if it emits
a beta particle
Which light source is more energy-efficient?
a fluorescent lamp
A nucleon is either
a proton or neutron
Which of the following can be projected onto a viewing screen?
a real image
Which of the following cannot travel in a vacuum?
a sound wave
Light travels fastest in
a vacuum
A beam of light travels fastest in
air
Optical fibers are now used by
all of these (surgeons, mechanics, engineers)
An atom that emits a certain frequency of light is
an absorber of the same frequency
The greater proportion of energy immediately converted to heat rather than light occurs in
an incandescent lamp
An atom with an imbalance of electrons to protons is
an ion
Radioactivity in the world is something
as old as the world itself
Objects infinitely far away are focused by a converging lens
at the focal point
According to Huygens' principle, every point on a wave
behaves as a source of new waves
If you wish to spear a fish with a regular spear, you should compensate for refraction between the air and water and throw your spear
below the sighted fish
If an alpha particle and a beta particle have the same energy, which particle will penetrate farther into an object?
beta particle
The hottest star is the star that glows
blue
Green light emitted by excited mercury vapor corresponds to a particular energy transition in the mercury atom. A more energetic transition might emit
blue light
Which has more energy per photon?
blue light
In the relationship E = hf for a photon emitted from an atom, the symbol E is used to represent the energy
both of these
Interference colors in a soap bubble give evidence that the soap film
both of these
When an alpha particle is ejected from a nucleus, the nucleus then has less
both of these
A beam of electrons has
both of these (particle and wave properties)
If a light signal and a radio signal were emitted simultaneously from Alpha Centauri, the first to reach Earth would be the
both would reach Earth at the same time
When a nucleus emits a beta particle, its atomic number
changes, but its mass number remains constant
Refraction causes the bottom of a swimming pool to appear
closer to the surface than it actually is
Energy released by the sun results from the process wherein atomic nuclei
combine
The most harmful radiations are those that
damage living cells
In the Bohr model of hydrogen, discrete radii and energy states result when an electron circles the atom in an integral number of
de Broglie wavelengths
The type of lens that spreads parallel light is a
diverging lens
Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more
electric charge
Consider plane waves incident upon a barrier with a small opening. After passing through the opening, the waves
fan out
Between nuclear fission and nuclear fusion, radioactive by-products are more characteristic of nuclear
fission
The energy of a photon depends on its
frequency
Which radiation has no electric charge associated with it?
gamma rays
A mixture of cyan and yellow pigments appears
green
When a nucleus emits a beta particle, its atomic number
increases by 1
Electrical forces inside a nucleus contribute nuclear
instability
Generally speaking, the larger a nucleus is, the greater its
instability
Light behaves primarily as a particle when it
interacts with matter
Colors seen when gasoline forms a thin film on water are a demonstration of
interference
Newton's rings are a demonstration of
interference
Most of the waves in the electromagnetic spectrum are
invisible
The nucleus with the most tightly bound nucleons is
iron
In both fission and fusion, mass
is converted to kinetic energy
Uranium-235, uranium-238 and uranium-239 are different
isotopes
Compared to its average speed in air, the average speed of a beam of light in glass is
less
Compared to the mass of a uranium nucleus before splitting, the pieces it splits into have
less mass
According to the uncertainty principle, the more we know about a particle's momentum, the less we know about its
location
Compared to ultraviolet waves, the wavelength of infrared waves is
longer
In the process of fluorescence, the input is high-frequency light and the output is
lower-frequency light
Look at a full-color picture in a magazine with a magnifying glass and you'll see that the inks used are
magenta, cyan, yellow, and black
Light is emitted when an electron
makes a transition to a lower energy level
In the photoelectric effect, the greater the frequency of the illuminating light, the greater the
maximum velocity of ejected electrons
At night an underwater scuba diver aims his flashlight beam toward the surface at an angle of 15 degrees with the normal. Upon emerging, the beam angle will be
more than 15 degrees
Different isotopes of an element have different numbers of
neutrons
There is a greater proportion of carbon-14 in
new bones
The atomic mass number of an element is the same as the number of its
nucleons
In the photoelectric effect, the brighter the illuminating light on a photosensitive surface, the greater the
number of ejected electrons
The half-life on an isotope is one day. At the end of three days, how much of the isotope remains?
one-eighth
An atom that absorbs a photon of a certain energy can then emit
only a photon of the same or lower energy
The photoelectric effect best demonstrates the
particle nature of light
Light will not pass through a pair of Polaroids when their axes are
perpendicular
Which experiment best demonstrates the particle-like nature of light?
photoelectric effect
Which of the following is a property of light waves, but not of sound waves?
polarization
The atomic number of an element is the same as the number of its
protons
Electric forces within an atomic nucleus tend to
push it apart
The source of the Earth's natural heat is
radioactive decay in the Earth's core
An excited atom decays to its ground state and emits a photon of green light. If instead the atom decays to an intermediate state, then the light emitted could be
red
As a solid is gradually heated, the first color to glow is
red
Magenta light is really a mixture of
red and blue light
The colored dots that make up the color on a TV screen are
red, blue, green
The critical angle for a transparent material is the angle at and beyond which all light within the material is
reflected
Compared to the wavelengths of visible light, the wavelengths of matter waves are relatively
small
Which of the following is fundamentally different from the others?
sound waves
Astronomers can tell whether a star is approaching or receding from Earth by
the Doppler effect
Compared to radio waves, the velocity of visible light waves in a vacuum is
the same
How many colors of ink are used to print full-color pictures?
three plus black
Light will almost always travel from one place to another along a path of least
time
When uranium emits a beta particle, the result is a
transuranic element
Light behaves primarily as a wave when it
travels from one place to another.
Light refracts when traveling from air into glass because light
travels slower in glass than in air
Which of the following photons has the greatest energy?
ultraviolet
Fluorescent minerals on display in museums are illuminated with
ultraviolet light
In a breeder reactor
uranium is converted into plutonium
The polarization axes of ordinary sunglasses are
vertical
The highest frequency light of those below is
violet
A mirage occurs for road surfaces that are
warm
When Rutherford had a stream of alpha particles hit a gold foil, most of the particles
went almost straight through
A diver shines light up to the surface of a smooth pond at a 10-degree angle to the normal. Some light passes into the air above, and the part that reflects back into the water makes an angle to the normal of
10 degrees
The half-life of carbon 14 is 5730 years. If a 1-gram sample of old carbon is 1/8 as radioactive as 1-gram of a current sample, then the age of the old sample is about
17,200 years
A certain radioactive isotope placed near a Geiger counter registers 160 counts per second. Eight hours later, the counter registers 10 counts per second. What is the half-life of the isotope?
2 hours
When radium (A = 88) emits an alpha particle, the resulting nucleus has atomic number
86
When U-238 emits an alpha particle, the nucleus left behind has
90 protons
When U-235 undergoes fission, the two nuclei that result have a total of
92 protons
When U-239 emits a beta particle, the nucleus left behind has
93 protons
