Ionizing Radiation- Lecture 2 Flashcards
Describe the atom and the three main particles that make up the atom:
atom is is the basic unit of matter (matter is anything that has mass and occupies a space)
includes: protons, neutrons & electrons
Define atomic number (3):
Atomic number (Z)
- number of protons
- same as number of electrons in a neutral atom
- determines the identify of the 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, 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, electrons 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 though spaces 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 straights 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 and mass:
alpha particle
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:
radio waves, infrared, UV, etc.
Examples of electromagnetic radiation (Waves Theory) that are ionizing:
X-rays, and gamma rays
Describe the energy and wavelength of ionizing electromagnetic radiation:
highest energy, lowest wavelength (shortest)
Electromagnetic radiation that has highest energy and shortest wavelength:
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
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 beams diverges over distance)
- travels at speed of light
- highly penetrating (short wavelength of 0.01nm to 0.1 nm)
- differentially absorbed by matter
- can ionize matter
7.produces biological changes
X-rays can be described as ___, ____, and no ____.
invisible, weightless, and no charge
X-rays travel in ___, the x-ray beam ____ over distance
straight lines; diverges
X-rays travel at:
speed of light
X-rays are highly ____, with a short wavelength of ____ to ____.
penetrating; 0.01nm to 0.1 nm
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 after short distances
The transmission of energy through space (vacuum) and matter:
Radiation
When the energy transferred is not sufficient to overcome binding energy:
E- is not ejected
When the transferred energy is not sufficient to overcome the 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 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)
True of False, the higher the mass and charge, the higher the LET:
false
True or False, microwaves are ionizing:
false
Considering elements A and B, is the following statement true or false?
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
true
