8/19: Ionizing Radiation Flashcards
- Anything that has mass and occupies a space
Matter
- What is the basic unit of all matter?
Atoms
- Nucleus =
a. Proton + neutron
- The atomic number represents what?
a. Number of protons
- The atomic mass =
a. Neutrons + protons
- In a neutral atom, there is a same amount of _______ as protons
Electrons
- What determines the identity of the atom?
a. Atomic number
- On the side of the element symbol, what do the 2 numbers represent?
a. Top = mass number
b. Bottom = atomic number
- This is the amount of energy required to remove an electron from its shell
a. Binding energy
- In what units do we measure binding energy?
a. eV (electron volts)
- Within an atom, which electrons are more tightly bound?
a. Inner (K>L>M)
- Atomic number is represented by what letter?
Z
- Atomic mass is represented by what letter?
A
- More protons = higher
Z
- If you have a High Z, then you have more protons, therefore what occurs with electrons?
a. More tightly bound
- The electron binding energy is related to the
a. Atomic number
- There is a direct relation between the electron binding energy and the
a. Atomic number
- If electrons = protons, you have a
a. Neutral atom
- The higher the (Z) then
a. The higher the electron binding energy
- This is the process of forming a positive and negative ion by removal of an electron from a neutral atom
Ionization
(T/F) to ionize an atom, we do NOT need sufficient energy to overcome the electrostatic force and free the electron
False, we need
- What do we need to create an ion pair?
a. External energy to remove a electron to create a positive/negative molecule
- Say that K = 10,000 binding energy. How much external energy do we need to knock off an electron?
a. At least 10,000
- What is true about ionization?
a. Photon energy/external energy must be greater than binding energy
b. Ion pair is formed
- This is the transmission of energy through space (vacuum) and matter
a. Radiation
- Radiation may occur in what 2 forms?
a. Wave theory
b. Quantum (particles) theory
- This explains the propagation of radiation
a. Wave theory
- This explains the interaction of radiation with matter
a. Quantum theory
- Do X-rays have weight/mass?
No
- Why is Wave theory electromagnetic radiation?
a. Movement of energy through space as a combination of electron and magnetic fields
- What 2 things do we need in wave theory?
a. Wavelength
b. Frequency
- This is the distance between 2 successive crests (top to top or bottom to bottom)
a. Wavelength
- This is the number of wavelengths passing a particular point in time (Hz)
a. Frequency
- What is the equation for wave theory?
a. C (speed of light) = frequency x wavelength
- High frequency and short wavelength =
a. High energy radiation
- Low frequency, long wavelength =
a. Low energy radiation
- This radiation does not have sufficient energy to eject an electron from the shells
a. Non-ionizing
- This radiation has sufficient energy to eject an electron from the shells
a. Ionizing
- What considers radiation as small bundles of energy called photons?
a. Quantum theory
- Quantum theory considers radiation as small bundles of energy called
a. Photons
- Each photon has 3 things according to Quantum theory?
a. Mass (eV) and Energy
b. Travels in straight lines at the speed of light
- Are photons/particles according to quantum theory charged or not?
a. Electrically charged
- What particles are NOT electrically charged?
a. Neutrons
b. X-rays
- What is particulate radiation?
a. photons
- At what point do we get ionizing radiation?
UV
- This is directly proportional to frequency, inversely proportional to wavelength
Energy
- High frequency means short wavelength →
a. High energy
- Low frequency means longer wavelength →
Low energy
- Lower velocity, higher charge, and bigger size =
a. Greater LET
- Less penetration because they lose their energy after short distances
a. Higher LET
- Do X-rays have weight?
No
- What are the properties of X-rays? (on every exam)
a. Invisible, weightless, no electric charge
b. Travels in straight lines
c. Travels at speed of light
d. Highly penetrating (short WL)
e. Differently absorbed by matter
f. Can ionize matter
g. Produce biological changes
- When the transferred energy is not sufficient to overcome binding energy, what happens to e-?
a. Not ejected
- Receiving e- is raised to higher energy within the orbit and this instantly causes what?
a. Gives up excess energy and returns to ground level
