Ionizing Radiation (Lec 2) Flashcards
Describe the atom & the three main particles that make up the atom:
Atom is the basic unit of matter (matter is anything that has mass & occupies a space)
Include: protons, neutrons & electrons
Define atomic number (3):
Atomic number (Z)
-number of protons
-same as number of electrons in a neutral atom
-determines the identity in a neutral atom
Define mass number (2):
Mass number (A)
-number of protons + neutrons
-weight of nucleus
Number of protons + neutrons:
mass number (A)
Label what each of the arrows is representing:
4: mass number (A)
2: atomic number (Z)
He: element symbol
Explain electron configuration:
Electrons organized into shells around the nucleus
Electron configuration:
Within a given atom, inner shell electrons are more:
Tightly bound
Electron configuration:
The closer the electron is to the nucleus:
The more attracted it is to the nucleus
Electron configuration:
What shell has the highest binding energy?
K shell
Electron configuration:
The binding energy needed to remove an electron is equal to:
The binding energy of K
Electron configuration:
What shell has a “middle” binding energy?
What shell has the lowest binding energy?
L shell
M shell
Explain binding energy:
The amount of energy required to remove an electron from its shell
What is binding energy measured in?
Electron Volts (eV)
Binding energy is closely related to:
Atomic number
Binding energy is closely related to atomic number, explain:
High Z –>
Low Z –>
High Z –> High binding energy (more protons, electrons are more tightly bound/harder to remove)
Low Z –> Lower binding energy (less protons, electrongs are less tightly bound/easier to remove)
Explain the process of ionization:
Process of forming a positive and negative ion by removal of an electron from a neutral atom
To ionize an atom, we need ______ to overcome _____ and free the ______
Sufficient external energy; electrostatic forces; electron
For the process of ionization, the amount of external energy to overcome the electrostatic forces to free the electron needs to be:
the same binding energy or more
Explains the propagation of radiation in form of waves:
Waves theory
What radiation theory involves “no mass, no charge” :
Waves theory
Movement of energy through space as a combination of electric and magnetic fields:
Electromagnetic radiation
Electromagnetic radiation can be _____ or _____
Ionizing or non-ionizing
Explains the interaction of radiation within the matter:
Quantum (particulate) theory
Considers radiation as small discrete bundles of energy called photons:
Quantum (particulate) theory
A small discrete bundle of energy:
Photon
In what theory does each photon have energy (eV), mass, and travels in a straight line at the speed of light:
Quantum (particulate) theory
In the quantum (particulate) theory, describe the properties of each photon: (3)
- has energy (eV)
- has mass
- travels in straight lines at the speed of light
List examples of particulate radiation (Quantum theory):
Alpha
Beta + (positron)
Beta - (electron)
Electron
Neutron
Proton
The particulate radiation (photon) described by the quantum theory that has the highest charge & mass:
Alpha
Explains the propagation of radiation:
Waves theory
Explains the interaction of radiation with matter:
Quantum (particulate) theory
Examples of electromagnetic radiation (waves theory) that are non-ionizing:
Radiowaves
infrared
UV
etc.
Examples of electromagnetic radiation (waves theory) that are ionizing:
X-rays
Gamma rays
Describe the energy and wavelength of ionizing electromagnetic radiation:
Highest energy, lowest (shortest) wavelength
Electromagnetic radiation that has highest energy and shortest wavelength would be described as:
Ionizing
Distance between two successive crests:
Wavelength
The number of wavelengths passing a particular point in time:
Frequency
Explain the relationship between frequency and wavelength of X-rays:
Inversely proportional
Which wave has a higher frequency?
Right wave
Which wave has more energy?
Right wave
Which wave has a greater wavelength?
Left wave
Which wave has lower energy?
Left wave
From point A to point C represents:
One wavelength
Frequency and wavelength are _____ proportional
Inversely
Explain how photon energy of electromagnetic radiation is related to frequency and wavelength:
Energy is DIRECTLY proportional to frequency and INVERSELY proportional to wavelength
Energy is _____ proportional to frequency and ______ proportional to wavelength
DIRECTLY; INVERSELY
High frequency means _____ wavelength and _____ energy
Short wavelength; high energy
Low frequency means _____ wavelength and _____ energy
Long wavelength; low energy
Discuss the properties of X-rays (7):
- invisible, weightless, no electric charge
- travels in straight lines (X-ray beam diverges over distance)
- travels at speed of light
- highly penetrating (short wavelengts of 0.01nm to 0.1nm)
- differentially absorbed by matter
- can ionize matter
- produces biological changes
X-rays can be described as ______, ______ and no ______
Invisible, weightless and no electric charge
X-rays travel in _____. The X-ray beam _____ over distance
Straight lines; diverges
X-rays travels at:
Speed of light
X-rays are highly ______, with a short wavelength of ____ to _____
penetrating; 0.01nm to 0.1nm
X-rays are ______ by matter
Differentially absorbed
X-rays can _____ matter
ionize
X-rays can produce ____ changes
biological
LET:
Linear energy transfer
Rate of loss of energy from a particle as it moves through matter:
Ionizing rate
The ionizing rate depends on: (3)
- velocity
- charge
- size
Describe the LET in the following situation:
Lower velocity, higher charge, bigger size —>
Greater LET
A higher LET has less _______
penetration
A higher LET has less penetration because they ______ after ______
lose their energy; short distances
the transmission of energy through space (vacuum) and matter:
Radiation
When the transferred energy is not sufficient to overcome binding energy:
E- is NOT ejected
When the transferred energy is not sufficient to overcome binding energy, E- is not ejected and the receiving E- is raised to a higher energy level within the orbit:
Excitation
What happens to an electron that undergoes excitation?
Instantaneously gives up this excess energy and returns to ground level
Which of the following is false regarding the wave theory of X-radiation?
a) x-rays have mass
b) increased frequency means short wavelengths
c) x-rays travel at the speed of light in a vacuum
d) the waves are formed as a combination of electric and magnetic fields
A
T/F: the higher the mass and charge, the higher the LET
F
T/F: Microwaves are ionizing
F
Considering elements A & B. Is the following statement T/F?
To remove an electron from the K shell of element B requires more energy than element A
Element A) atomic number 100
Element B) atomic number 110
T
