Chapter 2 Flashcards
What was Bohr’s theory?
Described the atom as having 3 fundamental properties - electrons, neutrons, and protons
What is the atom made of?
Protons and nuetrons
What makes up the mass number?
Protons + neutrons
What does the atomic number represent?
Number of protons
The number of protons also equals the number of:
Electrons
What creates binding energy?
Neutrons and protons having a neutral and positive charge
Electons orbit starting with the letter:
K
How are electrons held in orbit?
Electron binding energy
Relationship between ebe and distance of the shell to the nucleus
The closer the shell to the nucleus, the stronger the ebe
How is ebe measured?
EV (electron volts)
If proton and electron number is the same, the atom is considered:
Neutral
What is cation?
One more proton than electron in the atom
What is anion?
One more electron than proton in the atom
The most electrons the OUTER shell can have is:
8
Electron shell formula:
2n^2
When an atom has an electron removed from its orbit, its considered:
Ionized
What 2 tungsten interactions occur at the anode?
Characteristic radiation
Brehmsstralung radiation
What is differential absorption?
Different atomic structures absorb differently
Properties of electrons
Have a variable speed
Has a very small mass
Negative charged
Properties of photons
Travel SOLONAA
Have no mass
Have no charge
What is the ebe of the K shell of Tungsten?
69.5 eV
What are the energies of the beam before half value layer?
Heterogeanous
What are the energies of the beam after the half value layer?
Homogenous
How many times can scatter hit matter and what happens to its power?
Two times
1/1000th
1/1000000th
What are the 3 types of scatter?
Compton
Photoelectron
Unmodified (Coherent)
What is Planck’s Constant?
6.626 x 10^-34
What is Characteristic Radiation?
An electron from the filament electron stream knocks out the k-shell electron from Tungsten
This produces a charactersistic photon along with cascading weaker photons from the filling back up of orbits
The atom will be unstable, and will pull electrons from other shells until its stable again
The initial Characteristic Xray is the only ones that are considered diagnostically useful
What is Brehm’s radiation?
“Breaking radiation”
The filament electron gets attracted to the nucleus and “breaks” or slows down and changes directions.
The resulting loss of energy creates a photon
Misses all of the other orbital electrons
Considered a weak photon and will be absorbed in filtration
When does Brehm’s radiation occur?
When photon energy is below 69.5 eV
How does the atomic number affect electrons and interactions?
Higher the atomic number, the greater the electrons, the greater the number of interactions
What letter represents Atomic number?
Z
What letter represents atomic mass?
A
What is Coherent Scattering?
Photon strikes an atom
Atom absorbs photon and becomes excited
Atom releases excess energy in the form of another photon
Proceeds in different direction
What is Compton scattering?
Photon strikes atom and uses a portion of energy to eject outer shell electron
Remainder of energy proceeds in different direction - can react with patient or exit
Ejected electron travels until combined with matter
What is Photoelectric Absoprtion?
Photon strikes inner shell electron and ejects it
Travels until it combines with other matter
Outer shell electrons move to fill vacancies and they release energy in the form of xrays known as secondary radiation
What type of scatter is least likely to occur?
Coherent
What type of scatter is the most common?
Compton
