P1 Flashcards
(102 cards)
1
Q
Fundamental building blocks of matter
A
Atom
2
Q
Smallest particle of an element
A
Atom
3
Q
Electron is discovered by
A
John Joseph
Thomson
4
Q
Proton is discovered by
A
Ernest Rutherford
5
Q
Neutron is discovered by
A
James Chadwick
6
Q
Consists of same number of protons
and electrons
A
Neutral atom
7
Q
– Consists of an extra or a lacking of e
– Can be positive or negative
A
Ionized Atom
8
Q
Consists of electrons
A
Orbital shell
9
Q
Central core of an atom
A
Nucleus
10
Q
Contains nearly all mass of the
atom
A
Nucleus
11
Q
Number of electron (outermost shell)
A
‒GROUP NUMBER
‒VALENCE STATE
12
Q
• Number of outermost electron shell
A
PERIOD NUMBER
13
Q
The strength of attachment of an
electron to the nucleus
A
Electron Binding energy
14
Q
The energy required to completely
remove an electron from the atom
A
Electron Binding Energy
15
Q
The number of protons in an atom
A
Atomic number
16
Q
The number of protons and neutrons
A
Atomic mass number
17
Q
The difference between the
atomic mass number and atomic
number
A
Neutron number
18
Q
‒ Atoms having nuclei with the same number of protons but different number of neutrons
A
Isotopes
19
Q
‒ Having the same number of neutrons but different number of protons
A
Isotones
20
Q
‒ Same number of nucleons but different number of protons
A
Isobars
21
Q
‒ Same number of protons as well as neutrons.
A
Isomers
22
Q
‒ Represents identical atoms except that they differ in their nuclear energy states.
A
Isomers
23
Q
Radioactivity is first discovered by ____
in ____.
A
Antonio Henri Becquerel, 1896
24
Q
A phenomenon in which radiation is given off by the nuclei of the elements
A
Radioactivity
25
This radiation can be in the form of particles, electromagnetic radiation, or both
Radioactivity
26
is the spontaneous emission of particles
and energy in order to become stable.
Radioactivity
27
The atoms involved in radioactivity are
radionuclides
28
Any nuclear arrangement is called a ___; only nuclei that undergo radioactive decay are ____.
nuclide, radionuclides
29
An unstable atomic nucleus sheds its excess energy in the form of either an _____.
If it still possesses excess energy after that, _____ are emitted in order to reach its steady state.
intranuclear electron (e−) (beta particle)
or a helium nucleus (an “alpha particle”)
gamma rays
30
‒ Original radionuclide
‒ Very unstable
‒ Longer half-lives
‒ Excited stated
PARENT
31
‒ Resulting radionuclide
‒ More stable
‒ Shorter half-lives
‒ Ground state
DAUGHTER
32
The time required for a quantity of
radioactivity to be reduced to one-
half its original value.
Physical Half life
33
The time required for the body to eliminate one-half of the dose of any substances by biological processes.
Biological half life
34
A combination of both T1/2 and Tb
Effective half-life
35
The time required for half of initial radioactivity to disappear from an organ or body by combination of excretion and physical decay
Effective half-life
36
Must always shorter than T1/2 or Tb
Effective half-life
37
Formula of the effective half-life
Formula: 1/Te= 1/T1/2 x 1/Tb / 1/T1/2 + 1/Tb
38
due to their negative charge and low mass, can be accelerated to high energies in linacs or betatrons.
Electrons
39
are normally bound to a (positively charged) nucleus.
Electrons
40
The number of electrons is equal to the number of protons in a ____ atom
neutral
41
all interact with matter by electrical forces and lose kinetic energy via excitation, ionization, and radiative losses.
Energetic charged particles
42
occur when charged particles lose
energy by interacting with orbital electrons.
Excitation and ionization
43
Excitation and ionization occur when charged particles lose energy by interacting with orbital electrons. These interactional, or collisional, losses refer to the ____ exerted on charged particles when they pass in proximity to the electric field generated by the atom’s electrons and protons.
coulombic forces
44
is the transfer of some of the incident particles' energy to electrons in the absorbing material, promoting
them to electron orbits farther from the nucleus (i.e., higher energy level).
Excitation
45
Occurs when energy transferred to an
electron does not exceed its binding
energy
Excitation
46
Following excitation, _____ occurs as the electron returns to a lower energy level releasing energy
de-excitation
47
Occurs when transferred energy exceeds the binding energy
Secondary Ionization
48
Electron is ejected from the atom
Secondary Ionization
49
Secondary Ionization results in an _____ consisting of an ejected electron and a
positively charged atom
ion pair
50
Secondary ionization occurs when the ejected electron has sufficient energy to produce further ionization, these
electrons are called
delta rays
51
As electron energy ______, the probability of energy loss via excitation _____.
decreases, increases
52
The number of primary and secondary ion pairs produced per unit length of the charged particle’s path is expressed in
_____
ion pairs (IP)/mm
53
As the alpha particle slows, the specific ionization increases to a maximum called the
Bragg peak
54
follow tortuous paths in matter as the result of multiple scattering events caused by coulombic deflections
(repulsion and/or attraction).
Electrons
55
Heavy charged particle results in a dense and usually ___ ionization track
linear
56
A particle that has a larger mass results in a dense and usually linear ionization track.
Alpha
57
‒Defined as the actual distance the particle travels.
Path length of a particle
58
‒Defined as the actual depth of penetration of the particle in matter.
Range of a particle
59
The path length of the ___ almost always exceeds its range.
electron
60
The path length and range of the ____ is being nearly equal
alpha particle
61
The amount of energy deposited per unit path length.
LINEAR ENERGY TRANSFER
62
LET is usually expressed in units of
eV/cm.
63
LET of a charged particle is ____ to the square of the charge and ____ to the particle’s kinetic energy.
proportional, inversely proportional
64
is the product of specific ionization (IP/cm) and the average energy deposited per ion pair (eV/IP).
LET
65
It is the result of interaction where the particle or photon deflects from its original path/trajectory.
Scattering
66
Scattering events in which the total kinetic energy of the colliding particles is unchanged is called
Elastic Scattering.
67
Scattering events that occurs with a loss of kinetic energy, the interaction is said to be
Inelastic Scattering
68
The radiation emission accompanying electron deceleration is called ___, a German word meaning ____
bremsstrahlung, braking radiation”
69
The deceleration of the high-speed electrons in an x-ray tube produces the
bremsstrahlung x-rays.
70
occurs when an electron ( e − ) and a positron ( e + , the electron's antiparticle) collide.
Electron–positron annihilation
71
happens when an X-Ray photon comes in, interacts with electron cloud and goes out. The X-Ray is scattered after this interaction but it has the same energy as it leaves.
Coherent Scattering/ Rayleigh/ Elastic
72
— Involves all of the electrons of
the atom in the interaction
Rayleigh Scattering
73
— Involves a single electron of the
atom in the interaction
Thomson Scattering:
74
(also called inelastic or nonclassical scattering) is the predominant interaction of x-ray and gamma-ray photons in the diagnostic energy range with soft tissue.
Compton scattering
75
This interaction is most likely to
occur between photons and
outer (“valence”) shell electrons.
Compton Scattering
76
Most common but the least desirable photon interaction
Compton Scatter
77
Results:
— Scattered x-ray
— Compton electron
— Change in direction
— Change in energy, frequency and
wavelength
Compton Scatter
78
In compton scattering with ____ of deflection , scattered x-ray retains at least 2/3 of its energy
180 degree
79
In compton scattering with ____ of deflection , no energy is transferred to Compton electron
0 degree
80
In compton scattering, an increased angle of deflection would cause ____ energy transferred to Compton electron
more
81
In Compton Scattering, a decrease angle of deflection would cause ___ energy transferred to Compton electron
less
82
Occurs when an incident x- ray
photon interacts with a tightly bound
electron
Photoelectric effect
83
Low-energy x-ray photons gives up
all its energy ejecting an inner-shell
electron
Photoelectric effect
84
Results:
—No scattered x-ray
—Photoelectron
—Total x-ray absorption
—Secondary x-rays
Photoelectric effect
85
▪ Major contributor to patient dose
▪ Production of high contrast image
Photoelectric effect
86
Photoelectric effect predominates in the lower energy ranges produced by ___ kVp
40-70
87
The conversion of a neutron boson into a subatomic particle and its antiparticle
Pair production
88
Occurs only with very-high- energy
photons of 1.02 MeV or greater
Pair Production
89
▪ Does not occur in radiography
▪ Useful in nuclear medicine
Pair production
90
Results:
▪ Incident photon disappears
▪ Incident photon is converted to
matter (pair electrons)
— Negatron
—Positron
▪ Annihilation reaction
Pair Production
91
Identical to a helium nucleus
Alpha Particle
92
Heaviest and least penetrating
form of radiation
Alpha
93
Carries an electronic charge
twice that of the proton
Alpha
94
Occurs in all radionuclides
Beta decay
95
Occurs much more frequently than
alpha particle
Beta decay
96
2 types of beta particle
Beta minus
Beta plus
97
Identical to electrons
Beta particle
98
The existence of neutrinos and antineutrinos was first suggested by ___ in ____, although it was ___ that provided
the name “neutrino”
Pauli, 1930, Fermi
99
Method of radioactive decay
that involves the capture of an
orbital electron most likely in
the K or L- shell by its nucleus
Positron decay
100
Similar to positron decay
Electron capture
101
There is no change in the atomic or mass number of the nucleus after the gamma decay, so it is termed an “ ____ ”
decay.
isomeric
102
A nucleus is not always fully stable (i.e., at its basal energy level) just after it decays; sometimes, the nucleus will be in a semi-stable state instead. The excess energy carried by the nucleus is then emitted
as ____ radiation.
gamma
