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atomic and nuclear physics
flashcards for Fedorchak's 222 physics test 4
86
Physics
Undergraduate 3
04/25/2010

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Term
electron
Definition
particles with a negative electric charge that orbit the atom's nucleus.
Term
protons
Definition
particles with a positive electric charge located in the nucleus of an atom
Term
neutrons
Definition
particles located in the nucleus of an atom
Term
positrons (or anti-electrons)
Definition
are "electrons" with a positive electric charge
Term
anti-protons
Definition
protons with a negative electric charge
Term
atomic weight
Definition
the physical mass of a single atom of an element
Term
eletron volt
Definition
another unit of energy that is used in measuring the kinetic energy of atomic phenomena since their dimensions are so small relative to the macroscopic world that we have been dealing with.
Term
isotopes
Definition
different forms of the same element that have the SAME number of PROTONS, but a different number of neutrons.
Term
isobars
Definition
different elementsthat have the same atomic mass number (i.e. they have the SAME net number of BARYONS [protons and neutrons])
Term
isotones
Definition
different elements that have the SAME number of NEUTRONS
Term
the Thomson Model
Definition
Thomson theorized that electrons and protons were combined together within a fixed sphere of an atom.
Term
The Rutherford Model
Definition
Rutherford suggested the presence of a particle with no electric charge, the neutron. His research  also showed that the electrons orbited a nucleus consisting of protons and neutrons.
Term
The Bohr Model
Definition
Bohr discovered that electrons did orbit the nucleus at discrete distances, that these shells of electrons had allowed numbers of electrons for each shell and that each shell corresponded to a discrete energy level.
Term
The Quantum Mechanics Model
Definition
instead of a single elctron in orbit at a defined radius "r", the quantum mechanical model of the Hydrogen atom still has the proton in the center of the atom, the electron is represented by a term we call the wave function, that models the wave and particle behavior of the electron in its orbit.
Term
ground state
Definition
the single electron is in its smallest radius corresponding to the lowest energy level.
Term
excited state
Definition
a higher energy level than its ground state
Term
The Lyman series
Definition
corresponds to all transitions to and from the n=1 shell.
Term
The Balmer series
Definition
corresponds to all transitions to and from the n=2 state
Term

The Paschen series

 

Definition
corresponds to all transitions to and from the n=3 shell.[genrally do not "see" this series because it corresponds to the infra-red spectrum]
Term
aspects of the Bohr Model
Definition

1. electrons move in a circular orbit around the proton under the influence of the electric force of attraction

2. only certain electron orbits are stable. In a stable state, an electron does not emit energy in the from of radiation.

3. radiation is emitted by the electron when transitioning from a more energetic stable state to another lower engergy stable state.

4. the size of the electron orbit is determined by the condition imposed by the electron's angular momentum.

Term
ionization energy
Definition
the amount of energy required to remove the electron from this shell of the hydrogen atom.
Term
fine structure
Definition
when the spectral lines of an atom are split, even in the absence of a magnetic field.
Term
Pauli Exclusion Principle
Definition
no two electrons can ever be in the same quantum state; therefore, no two electrons can have the same set of quantum numbers.
Term
Hund's Rule
Definition
when an atom has orbitals of equal energy, the order in which they are filled by electrons is such that a maximum number of electrons have unpaired spins.
Term
strong nuclear force
Definition
strongest fundamental field force that we know about. interacts through a physical quantity called the color charge.
Term
weak nuclear force
Definition
is about 12 orders of magnitude weaker than the magnitude of the Coulomb force. interacts through a physical quantity known as the color flavor.
Term
electroweak nuclear force
Definition
the strong nuclear force and the weak nuclear force are simply different aspects of this one fundamental force.
Term
binding energy of the nucleus
Definition
indirect way for measuring the strong nuclear force.
Term
linear accelerators
Definition
allelerate objects in a straight line
Term
cyclotrons and synchrotrons
Definition
accelerate objects in a circular path.
Term
hadrons
Definition
particles that interact primarily through the strong nuclear force. They are composed of smaller elementary particles that we call "quarks".
Term
mesons
Definition

lighter particles that have integer spins

 

decay into electrons, positrons,neutrinos, anti-neutrinos, as well as photons

 

composed of a quark and one anti-quark pair

Term
baryons
Definition

heavier particles that have 1/2 integer spins

 

protons and neutrons together

 

composed of 3 quarks

Term

leptons

 

Definition
particles that interact through the weak nuclear force. All have a spin of 1/2. Currently 6 are known.
Term
The 6 quarks
Definition

1. up quark (u)

2. down quark (d)

3. charmed quark (c)

4.  strange quark (s)

5. top or truth quark (t)

6. bottom or beauty quark (b)

Term
The 6 anti-quarks
Definition

1. anti-up quark (u)

2. anti-down (d)

3. anti-top quark (t)

4. anti-bottom (b)

5. anti-charmed quark (c)

6. anti-strange quark (s)

Term
conservation of electric charge
Definition
can be summarized in terms that the net electric charge of an object before an event or interaction much equal the net electric charge afterwards.
Term
conservation of baryon number
Definition
can be summarized in terms that the net number of baryons of a system before an event or interaction must equal the net baryons afterwards.
Term
color force
Definition
interacts with quarks through the color charge which is analogous to the electric field and electric charge.
Term
characteristics of the color force
Definition

1. there are three different color states or "flavors" (red, green, and blue)

 

2. each color state is characterized by two conserved color charges.

 

3. only color states with zero value for the net color charge are observable as free particles.

Term
alpha decay
Definition
emission of a single alpha particle consisting of two protons and two neutrons from the atom's nucleus.
Term
beta decay
Definition
the emission of a beta particle and an associated neutrino from the atom's nucleus resulting from the decay of a nucleon into two oppositely charged particles.
Term
gamma decay
Definition
the emission of a single gamma particle or photon from the atom's nucleus.
Term
electron capture
Definition
occurs when an atom's nucleus absorbs an electron, the electron "merges" with the proton to produce a neutron and the nucleus then emits a neutrino.
Term
proton decay
Definition
occurs when an atom emits a proton from its nucleus.
Term
alpha particle
Definition

consists of two protons and two neutrons

 

largest and heaviest of the nuclear decay particles

 

high probability of interaction with human tissue and matter

 

least dangerous when outside the body

 

most dangerous of the three forms of decay when internal to the body

Term
beta particles
Definition

two types: emitted electron or positrons

 

the lighter electron or positron is emitted from the nucleus as a particle with some associated kinetic energy while the beavier particle remains in the nucleus

 

dangerous when internal to the body

 

when external to the body they can be stopped by a simple shield.

Term
gamma particles
Definition

consists of an emitted photon coming from the nucleus of the atom

 

when external to the body, gamma particles can be stopped by heavier shielding

 

dangerous when internal to the body because the particle's energy is directly transferred to the cells in the body.

Term
radiological half-life
Definition
half life of an atom is the time required for one-half of the original element to undergo radioactive decay into another element or isotope.
Term

carbon dating

 

Definition

most common methods used for dating biological samples.

 

Term
limitations of carbon dating
Definition

1. you can only date material that was alive at some point.

 

2. you can only accurately date material with an age with 10 half-lives o the radioactive element.

 

3. your dating of the material is the date that the object died, not the date that it was manufactured into the object.

Term
the Roentgen
Definition
is an older term for radioactive absorbed dose.
Term
the rad
Definition
has replaced the roentgen for most scientific applications for the radiological absorbed dose.
Term
the Gray
Definition
is the formal MKS unit for radiological absorbed dose designed to replace the older [rad] units of absorbed dose for scientific and medical usage.
Term
the rem
Definition
difines the biological impact of radiation on tissue
Term
The Sievert
Definition
the formal SI unit for radiological absorbed dose equivilant that was supposed to replace the REM for scientific and medical usage.
Term
nuclear fission
Definition
involves the splitting of a heavier atom into two or more lighter atoms plus the release of extra neutrons and energy.
Term
nuclear fusion
Definition
involves the combining together of two lighter atoms to produce a heavier atom plus the release and energy.
Term
fission fragments
Definition
fission byproducts
Term
binary fission
Definition
results in two fission fragment elements.
Term
tertiary fission
Definition
takes place where three fission fragment elements are produced.
Term
nuclear cross-section
Definition
the probability for neutrons to be absorbed by the nucleus of each fissionable atom based on the kinetic energy of the neutron.
Term
reproduction constant [K]
Definition
the rate of production of neutrons within a reactor
Term
K=1
Definition
the reactor is critical, each nuclear fission created sufficient neutrons to create one additional nuclear fission.
Term
K<1
Definition
the reactor is said to be subcritical, each nuclear fission event does not produce more then one nuclear fission event.  The subcritical reactor will die out to zero fission events.
Term
K>1
Definition
the reactor is said to be supercritical,  each nuclear fission event produces more than one nuclear fission event. If K is much greater than 1 you will have a runaway fission event.
Term
advantages of nuclear fission
Definition

1.  we can do nuclear fission now

 

2.  the cost of electricity produced by nuclear fission reactors is less than other fossil fuels.

 

3. nuclear fission reactors do not pollute the environment with organic emisions.

 

4.  nuclear fission reactors have long operational lives

Term
disadvantages of nuclear fission
Definition

1. fissionable elements are not common.

 

2.it is expensive to enrich fissionable fuel elements to required concentrations.

 

3. the majority of fissionable by-products are highly radioactive with long half lives.

Term
n
Definition
principle quantum number
Term
l (cursive L)
Definition
oribital quantum number [k=n-1]
Term
m
Definition
orbital magnetic quantum number [-l, -1+l, 0, 1, 1+l, and l]
Term
m(sub s)
Definition
spin quantum number [+1/2 or -1/2]
Term
nuclear fusion
Definition
involves the combining of two lighter atoms resulting in a heavier atom plus the release of energy.
Term
How does nuclear fusion occur?
Definition
Heat the nuclear fusion fuel elements to an extremely hight temperature to strip away the electrons from the elements and form plasma. The plasma nuclei are forced close enough together to allow the strong nuclear force to dominate over the Coulomb Force of repulsion.
Term
What are the most common nuclear fusion reactions?
Definition
deuterium-deuterium and deuterium-tritium.
Term
What are Lawson's Criterion?
Definition
plasma ionization density and plasma confinement time
Term
plasma ionization density
Definition
number of nuclei per unit volume.
Term
plasma confinement time
Definition
the time that nuclei are maintained at a suffecient temperature greater or equal to that required for the reaction to take place.
Term
Laser Inertial Confinement Reactors
Definition
use the implosion effect from multiple lasers to collapse the fuel pellets to achieve Lawson's criterion and contain the nuclear fusion reaction.
Term

Tokamak Reactors or

Magnetic Confinement Fusion Reactors

Definition
use magnetic fields to collapse the fuel pellets and contain the nuclear fusion reaction.
Term
Challenges related to nuclear fusion
Definition

1. putting more energy into creating the nuclear fusion process than we are getting from the nuclear fusion.

 

2. challenges in refueling the nuclear fusion reactor while sustaining the nuclear fusion process and energy production.

 

3. how do we remove spent fuel while sustaining the nuclear fusion process?

Term
advantages of nuclear fusion
Definition

1. virtually limitless supply of inexpensive fuel

 

2. no long lives radioactive byproducts

Term
disadvantages of nuclear fusion
Definition
we cannon support continuous controllable nuclear fusion reactions for energy production with our current levels of technology.
Term
Cut off year for Carbon dating
Definition
57,000 years
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