Physics 1320
highest energy to lowest energy
3rd excited state -> 2nd excited state -> 1st excited state -> ground state
How can you predict the number of silver atoms there are in the second before the time equal to 0 seconds on the graph?
Find the proportion of atoms that remains after 1 second. Then increase the number of original atoms by the same proportion.
Which of these is electromagnetic radiation?
gamma radiation
With respect to particles and waves, Bohr's principle of complementarity _______.
supports different ways of interpreting them
A beam of electrons has
wave and particle properties
The half-life on an isotope is one day. At the end of three days, how much of the isotope remains?
1/8
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
17200 years
When a nucleus decays by emitting an alpha particle, its atomic number decreases by ______.
2
largest to smallest distances
3rd excited state -> 2nd excited state -> 1st excited state -> ground state
A hypothetical atom has four distinct energy states. Assuming all transitions are possible, how many spectral lines can this atom produce?
6
When radium (A = 88) emits an alpha particle, the resulting nucleus has atomic number
86
The energy released by nuclear fission is in accord with the celebrated equation _______.
E = mc 2
The ratio of the energy of a photon to its frequency is
Planck's constant.
Increase the frequency to its maximum value. How does the current change if you increase the intensity of the light?
The current increases continuously
With the intensity at about half of maximum, how does the current change when you increase the frequency of the light?
The current remains zero until a certain frequency, at which it increases abruptly and remains constant thereafter.
Does the de Broglie wavelength of a proton become longer or shorter as its velocity increases?
The de Broglie wavelength of a proton becomes shorter.
How does the minimum frequency of light needed to produce the current change if we increase the intensity of light?
The minimum frequency needed to produce a current does not change if you increase the intensity.
Which of these typically undergoes a chain reaction?
U-235
The discovery of radioactivity closely followed the discovery of _______.
X-rays
If a beam of red light and a beam of blue light have exactly the same energy, which beam contains the greater number of photons?
a beam of red light
Which laser beam carries more energy per photon - a red beam or a green beam?
a green beam
Which has more energy - a photon of visible light or a photon of ultraviolet light?
a photon of ultraviolet light
In the equation E = hf, the h is _______.
a proportionality constant
Bohr's correspondence principle states that if a new theory is valid, it must _______.
account for the verified results of older theories
According to quantum physics, measuring the velocity of a tiny particle with an electromagnet
affects the velocity of the particle.
An element that undergoes radioactive decay becomes _______.
an entirely different element
An atom with an imbalance of electrons to protons is
an ion
When emitted, a photon behaves as a particle, and when traveling it behaves _______.
as a wave
Most alpha particles fired at a gold foil pass through undeflected because the
atoms of gold, like any others, are mostly empty space
If an alpha particle and a beta particle have the same energy, which particle will penetrate farther into an object?
beta particle
Which color light is the result of a greater energy transition, red or blue?
blue
Which of the following isotopes is radioactive?
carbon-14
When a nucleus emits a beta particle, its atomic number
changes, but its mass number remains constant.
Which of these ejects the greatest amount of dangerous radiation into the atmosphere?
coal-fired power plants
We now consider the Bohr model of the atom to be
defective and oversimplified, but still useful
When a nucleus decays as the result of the emission of an electron, the atomic mass _______.
does not change
When the frequency of a photon is doubled, the energy it carries _______.
doubles
What kind of force pushes particles in the atomic nucleus apart?
electric force
The great discovery of J.J. Thompson was the _______.
electron
The sources of X-rays and gamma rays, respectively, are
electron clouds and the atomic nucleus.
The spectra of atoms reveal their _______.
electron structure and atomic identity
The number of _______ identifies whether an atom carries a charge as an ion or is neutral.
electrons
What exactly is ejected in the photoelectric effect?
electrons
Some alpha particles fired through a gold foil bounce backward by
electrostatic repulsion when close to gold nuclei.
When a gamma ray is emitted by a nucleus, the nucleus then has less
energy
Two photons have the same wavelength. They also have the same
energy frequency
Which type of radiation - alpha, beta, or gamma - predominates within an enclosed elevator descending into a uranium mine?
gamma
Which radiation has no electric charge associated with it?
gamma rays
X-rays are most similar to which of the following - alpha, beta, or gamma rays?
gamma rays
X-rays are similar to
gamma rays
According to quantum physics, measuring the temperature of lava from a distant volcano by photographing its color with a telescopic camera
has no effect on the temperature of the lava
X-rays may be regarded as
high frequency radio waves
Photons making an image formed with feeble light arrive _______.
independently
According to Schrodinger, an electron can exist momentarily _______.
inside the atomic nucleus
Generally speaking, the larger a nucleus is, the greater its
instability
Light behaves primarily as a particle when it
interacts with matter
Bohr stated that electrons in an atom can undergo _______.
interference
The more information one has about the energy of an electron, the less certain one is about
its position the time it has that energy
All the uranium in today's deposits in the future will become _______.
lead
The fate of the world's uranium supply is to eventually become
lead
According to the uncertainty principle, the more we know about a particle's momentum, the less we know about its
location
An excited hydrogen atom is capable of emitting radiation of
many more than 3 frequencies.
When an alpha particle is ejected from a nucleus, the nucleus then has less
mass and charge
In the photoelectric effect, the greater the frequency of the illuminating light, the greater the
maximum velocity of ejected electrons.
The Bohr model of the atom is akin to a
miniature solar system.
The wavelength of a matter wave is inversely proportional to its _______.
momentum
Different isotopes of an element contain a different number of ______.
neutrons
Different isotopes of an element have different numbers of
neutrons
There is a greater proportion of carbon 14 in
new bones
Carbon-14 in the atmosphere is transformed from _______.
nitrogen
When thorium (A = 90) emits a beta particle, the resulting nucleus has atomic number
none of these
When a nucleus emits a gamma ray, it _______.
none of these statements are correct
Which of these makes up the least radiation in the everyday environment?
nuclear power plants
The atomic mass number of an element is the same as the number of its
nucleons
If a certain isotope has a radioactive half-life of 10 years, how much of the isotope will remain at the end of 20 years?
one quarter
The strong force is one of the four fundamental forces in nature, and exists _______.
only between particles in the nucleus
Carbon dating requires that the object being tested contain
organic material
Does the photoelectric effect depend on the wave nature or the particle nature of light?
particle nature
The photoelectric effect best demonstrates the
particle nature of light.
A lump of energy associated with light is called a
photon. quantum
The entity that is simultaneously uncertain in Heisenberg's uncertainty principle for momentum is _______.
position
The atomic number of an element is the same as the number of its
protons
The number of ______ identifies the type of element
protons
Electric forces within an atomic nucleus tend to
push it apart
A central feature of Bohr's model of the atom is _______.
quantum jumps of energy
According to Niels Bohr, an electron in an excited state could give off
several photons in a series of transitions to the ground state.
Compared to the wavelengths of visible light, the wavelengths of matter waves are relatively
small
When a beta particle is ejected from a nucleus, the nucleus then has slightly
smaller mass and significantly greater charge.
A quantum of light is a _______.
smallest lump of light
The great discovery of Rutherford was _______.
the atomic nucleus
An electron and a baseball move at the same speed. Which has the longer wavelength?
the electron
When a clean surface of potassium metal is exposed to blue light, electrons are emitted. If the intensity of the blue light is increased, which of the following will also increase?
the number of electrons ejected per second
Orbital electrons do not spiral into the nucleus because of
the wave nature of the electron.
Light behaves primarily as a wave when it
travels from one place to another
It's impossible for a hydrogen atom to emit an alpha particle.
true
The uncertainty principle applies not only to momentum and position, but also to energy and time. This statement is
true
The mass of an atomic nucleon is nearly
two thousand times the mass of an electron.
The photoelectric effect is best stimulated by _______.
ultraviolet light
In the equation E = hf, the f stands for
wave frequency as defined for sound, radio, and light waves
When Rutherford had a stream of alpha particles hit a gold foil, most of the particles
went almost straight through