Unit 1 Flashcards
1
Q
What are the fundamental building blocks of nature?
A
Atoms
2
Q
Fundamental Atom Structure:
A
Nucleus: Protons and Neutrons
Electron Shells: Electrons
3
Q
3 basic terms to describe an atom:
A
- Atomic Number
- Atomic Mass
- Atomic Weight
4
Q
What is Atomic Number?
A
Number of protons in the nucleus of an atom.
5
Q
Different ways of saying Atomic Number:
A
- Z-Number
- Proton Number
- Atomic Number
6
Q
Where can the atomic number of an element be found?
A
Periodic Table
7
Q
How is the atomic number of an atom indicated in the periodic table?
A
Superscript
8
Q
What is the Atomic Mass?
A
The mass of protons, neutrons, and electrons.
9
Q
Is the atomic mass a precise number?
A
Yes
10
Q
How is atomic mass indicated?
A
An exact number with a decimal
11
Q
What is atomic weight?
A
The total number of protons and neutrons present within the nucleus of an atom.
12
Q
Which atoms are electrically neutral?
A
Stable atoms
13
Q
The outer shell of an electron never contains more than 8 atoms. What is this rule?
A
Octet Rule
14
Q
The atomic number (z) of an atom is equal to the number of _____ in its nucleus.
A
Protons
15
Q
Max number of electrons per shell =
A
2n squared
16
Q
Ionization steps
A
1) Ionizing radiation hits an electron
2) Electron is knocked out of orbit
3) Ion pair remains
17
Q
Ion Pair
A
Atom (+1)
Free Electron (-1)
18
Q
What is an Ion?
A
An atom that gains or loses an electron
19
Q
Types of Ionizing Radiation
A
1) Particulate Radiation
2) Electromagnetic Radiation
20
Q
Particulate Radiation acts as ____
A
Particles
21
Q
What particles are in particulate radiation?
A
Alpha Particles
Beta Particles
22
Q
Electromagnetic Radiation acts as ___
A
Waves and Particles
23
Q
2 types of Electromagnetic Radiation
A
X-rays
Gamma Rays
24
Q
Are X-rays and Gamma Rays capable of ionizing?
A
Yes
25
Gamma Rays origin
Within the nucleus
26
X-rays origin
Outside of the nucleus within the electron shells
27
The 3 atomic forces that influence the behavior of the fundamental particles:
1. Strong Nuclear Force
2. Centripetal Force
3. Centrifugal Force
28
Definition of Strong Nuclear Force:
Force associated with protons and neutrons within the nucleus
29
Definition of Centripetal Force
Force involving the nucleus and the orbiting electrons
30
Definition of Centrifugal Force
Involves just the electrons
31
Quarks:
Exchange force carrying particles between each other to give rise to the strong force.
32
Gluons:
The force carrying particles
33
What makes up protons and neutrons?
Quarks
34
Which atomic force only operates at extremely small distances?
Strong Nuclear Force
35
The force of attractions between protons and neutrons
Strong Nuclear Force
36
Protons could not live in the nucleus without the force of attraction with the ____
Neutrons
37
Which atomic force is the strongest attractive force?
Strong Nuclear Force
38
Which atomic force is 137x more powerful than electromagnetic?
Strong Nuclear Force
39
Why can’t electromagnetic hold neutrons to protons?
Neutrons aren’t charged
40
What is the center seeking force involving the nucleus and electrons?
Centripetal Force
41
With Centripetal Force, the negative electrons are pulled towards _____
The positive nucleus
42
A force that acts to pull a spinning objects away from the center
Centrifugal Force
43
Which force balances Centripetal Force and pulls away from the nucleus?
Centrifugal Force
44
3 Types of Energy
1. Nuclear Binding Energy
2. Electron Binging Energy
3. Kinetic Energy of Electrons
45
What is Nuclear Binding Energy?
The minimum energy that would be required to disassemble the nucleus of an atom into its component parts.
46
What is Electron Binding Energy?
The energy required to keep electrons within their orbital shells
47
Electron Binding Energy depends on what 2 factors?
1. Distance away from the nucleus
- an electron closer to the nucleus will have a higher electron binding energy.
2. Total number of electrons within the atom.
48
K-shell binding energies increase as _____ increases
Atomic Number (Z)
49
What is the Kinetic Energy of Electrons?
The amount of energy associated with an electrons motion.
50
The faster an object moves, the more _____ it possesses.
Energy
51
As electron shell radius increases, ____ _____ increases
Electron Velocity
52
Do electrons in outer orbits travel faster or slower?
Faster
53
Do innermost shells move fastest or slowest?
Slowest
54
Why do the innermost shells move slowest?
Have little kinetic energy
55
What are valence electrons?
The outermost shell of an atom
56
What is Radioactivity?
The rate of decay or disintegration of radioactive material
57
Atoms are either ____ or _____
Stable or Unstable
58
Atoms are stable if:
The forces among the particles that make up the nucleus are balanced
59
If atoms are unstable, they are ____
Radioactive
60
An atom is unstable if:
The forces are unbalanced - if the nucleus has an excess of internal energy
61
What may cause the instability of an atom’s nucleus?
An excess of either neutrons or protons
62
How does a radioactive atom attempt to reach stability?
By throwing off nucleons (protons or neutrons), or by releasing energy in other forms.
63
What is Radioactive Decay?
The process by which atoms with unstable nuclei emit excess energy.
64
What are Radionuclides?
Nuclear arrangement resulting in radioactivity
65
Radionuclides can release either _____ or ____
Particles or Photons
66
Any time a photon comes from the nucleus, it is a _____
Gamma Ray
67
If Radionuclides release a small amount, it is releasing
Photons
68
If Radionuclides release a large amount of, they’re releasing,
Particles
69
What is Radioactive Half-Life?
The time required for a quantity of radioactivity to be reduced to one-half of its original value
70
How is radioactive half life represented?
T 1/2
71
How is radioactivity measured?
Becquerels
72
What are the 2 ways a radionuclide can release radiation from the nucleus?
1. Particles
(Particulate Radiation: Alpha or Beta particles)
2. Energy
(Electromagnetic Radiation: Gamma Rays (photons))
73
What is Particulate Radiation?
The release of particles from the nucleus
74
2 main types of Particulate Radiation?
1. Alpha Particles
2. Beta Particles
75
What are Alpha Particles?
Particles consisting of 2 protons and 2 neutrons and 0 electrons
76
Alpha Particles are also referred to as
“helium nucleus”
77
Alpha Particles symbol
ą
78
Alpha Particles charge
+2 (double positive charge)
79
Alpha Particles atomic mass number
4
80
Alpha Particles
Total Energy:
Range:
Origin:
Total Energy: 4-7 mev
Range: 1-10 cm. in air (then slows down, picks up 2 electrons, and becomes a helium atom)
Origin: Heavy radioactive nuclei
81
Alpha particles are highly ionizing, attracts electrons, electron static attraction
82
What particles can be stopped very easily?
Alpha Particles
83
Least penetrating form of ionizing radiation
Alpha Particles
84
Most damaging form of ionizing radiation
Alpha particles
85
Why are alpha particles the most damaging?
Due to the amount of concentrated energy that is deposited
86
What is Alpha Emission?
Throwing out of neutrons or protons from the nucleus of a heavy atom
87
When particles are thrown out, what happens to the element?
It changes it
88
Anytime you have excess energy in the nucleus that is greater than the binding energy, it can’t contain it and it throws out particles.
89
Always 2 ____ and 2 ____ for an alpha particle
Protons and Neutrons
90
What are Beta Particles?
Particles emitted from the nucleus that resemble electrons.
91
How do beta particles resemble electrons?
Same size and atomic mass, but different origin and energy.
92
High speed electrons released from the nucleus of a radioactive material
Beta particles
93
Beta Particles symbol
B
94
Beta particles have which charge?
Can be positive or negative
95
Beta Particles
Charge:
Atomic Mass Number:
Charge: -1 or +1
Atomic Mass Number: 0
96
Beta Particles
Total Energy:
Range:
Origin:
Total Energy: 0-7 mev
Range: 0-10 meters in air (then slow down)
Origin: Radioactive nuclei
97
Why are beta particles less damaging than alpha particles?
Due to less energy being deposited in as concentrated of an area
98
Beta Particles are strong and penetrating
99
What can stop Beta Particles?
Aluminum
100
Penetration and damage have a ____ relationship
Indirect
101
List the subatomic particles that comprise a typical atom:
Protons, Neutrons, and Electrons
102
Define "Atomic Number"
The number of protons within the nucleus of an atom.
103
Define "Atomic Mass"
The mass of protons, neutrons, and electrons.
104
Define "Atomic Weight"
Total number of protons and neutrons present within the nucleus of an atom.
105
Define "Z-Number"
Number of protons in an atom.
106
Define "Valence Shell"
The outermost shell of an atom
107
What is the maximum number of electrons possible in the "P" shell?
72
108
Define "Ionization"
The addition or removal of an atom
109
List two things that distinguish alpha and beta particles from x-rays:
Particles originate from inside the nucleus as an unstable atom.
Particles have mass, which means they can be slowed down.
Particles have charges, and x-rays do not.
110
List the one thing that distinguishes a gamma ray from an x-ray:
Origin
111
Define centrifugal force
A force that acts to pull a spinning object away from the center.
111
Define Electron Binding Energy
The energy required to keep electrons within their orbital shells.
Energy increases from inner to outer
112
Define "Centripetal Force"
Center-seeking force involving the nucleus and electrons.
112
Define "Octet Rule"
The maximum number of electrons allowed in the valence shell of any atom is 8.
*Can have a number other than 8, but 8 is the max*
113
Define "Radioactivity"
The rate of decay or disintegration of radioactive material.
113
Define "Radionuclide"
Nuclear arrangement resulting in radioactivity.
113
Which form of particulate radiation can be stopped with a piece of paper?
Alpha Particles
113
Define "Radioactive Half-life"
The time required for a quantity of radioactivity to be reduced one-half of its original value.
113
Which form of ionizing radiation is the most damaging?
Alpha
114
Why does increasing kVp improve the average quality of the primary beam?
Increased kev of the electrons/photons
114
Which form of photon production involves the process of ionization?
Characteristic
115
What percentage of the primary beam will be made of characteristic photons with a kVp setting of 65?
0
115
Which shell is shell 1?
K
115
We use the term "kev" to discuss?
Kinetic energy of electrons from cathode to anode.
Kinetic energy of electrons in the shell.
Kinetic energy of the resulting x-ray photons.
115
Why is tungsten an "efficient" producer of x-ray photons?
High z-number (makes it more attractive)
High melting point
115
The production of a bremsstrahlung photon involves an interaction between an incident electron and what else?
The nucleus of a tungsten atom.
115
Which portion of the primary beam is the "discrete" portion?
Characteristic
70 kvp = 10%
100 kvp = 15%
115
Define "electromotive force"
Another term for kVp/potential difference.
Voltage of the tube.
115
What is the max number of electrons that can be in "K" shell?
2
115
Which shell is shell 2?
L
115
Which shell is shell 5?
O
116
Which shell is shell 3?
M
116
What is the max number of electrons that can be in "L" shell?
8
116
Which shell is shell 4?
N
116
Which shell is shell 6?
P
116
What is the max number of electrons that can be in "N" shell?
32
116
Which shell is shell 7?
Q
117
What is the max number of electrons that can be in "M" shell?
18
117
What is the max number of electrons that can be in "O" shell?
50
117
What is the max number of electrons that can be in "P" shell?
72
117
What is the max number of electrons that can be in "Q" shell?
98
