Final Review

Question 1

Calculate the mass defect for sulfur-32. 
Z= 16
Aw= 31.972 g 
Proton mass= 1.00727u
neutron mass= 1.00866u

Answer 1

0.283

Question 2

what is the nuclear binding energy for sulfur-32?
Z= 16
Aw= 31.972 g
Proton mass= 1.00727u
neutron mass= 1.00866u
Please answer in MeV to one decimal place

Answer 2

263.5

Question 3

what is the maximum nunber of electrons in the M shell?

Answer 3

18

Question 4

How many atoms are in a gram of potassium-38?
Aw= 39.10g
Na= 6.022x10^23 atoms/g

Answer 4

1.50x10^22 atoms

Question 5

which is true regarding the Heisenberg Uncertainty Principle?

A. It is impossible to know the exact position and momentum of an electron
B. the energy of a nucleus cannot be accurately measured
C. it is impossible to know the exact mass of a nucleus
D. none of the above

Answer 5

A. It is impossible to know the exact position and momentum of an electron

Question 6

Which of the following is a true statement regarding the Pauli Exclusion Principle?
A. two or more elctrons cannot be in a n orbital at the same time
B. two or more electrons in a electron shell cannot have the same energy
C. more than one electron cannot be in the same quantum state at the same time
D. the higher the binding nergy of the outer shell ectrons prevent them from creating characteristic x-rays

Answer 6

C. more than one electron cannot be in the same quantum state at the same time

Question 7

Which combination of neutrons and protons in the nuclei below is most stable?
Magic Numbers= 2, 8, 20, 28, 50, 82, 126

A. 22 protons & 28 neutrons
B. 22 protons & 26 neutrons
C. 20 protons & 28 neutrons

Answer 7

C. 20 protons & 28 neutrons

Question 8

T/F: every gram atomic weight of a substance contains the same number of atoms

Answer 8

true

Question 9

the energy that hold an electron in the atom is called the 
A. strong nuclear force
B. energy potential well
C. electron binding energy
D. weak nuclear force

Answer 9

C. electron binding energy

Question 10

if a radionuclide has a decay constant of 0.123/minute, how much will remain after 20 minutes?

Answer 10

8.5%

Question 11

If we start with 25 MBq of a radioactive material with a half-life of 27 days, how much will be left after 95 days?

Answer 11

2.2 MBq

Question 12

What is the decay constant for iodine-125 (half-life = 60.2 days).

Answer 12

0.0115 day-1

Question 13

A nuclear reaction which releases additional energy in the reaction is known as
A. nucleonic 
B. energetic
C. endoergic
D. exoergic

Answer 13

D. exoergic

Question 14

Which type of radioactive decay only occurs with radionuclides with high atomic numbers?
A. beta particle dcay 
B. electron capture
C. alpha particle decay
D. internal conversion

Answer 14

C. alpha particle decay

Question 15

Which of the following is true regarding radionuclides in Secular Equilibrium?
A. neither answer is correct
B. The activity of the daughter radionuclide equals the activity of the parent radionuclide.
C. both answers are correct
D. The half-life of the daughter radionuclide is much greater than the half-life of the parent radionuclide.

Answer 15

B. The activity of the daughter radionuclide equals the activity of the parent radionuclide.

Question 16

For low Z materials the stable elements have a nucleus with
A. an approximately equal number of protons and electrons.
B. an approximately equal number of protons and neutrons.
C. a higher ratio of protons to neutrons
D. a higher ratio of neutrons to protons

Answer 16

B. an approximately equal number of protons and neutrons.

Question 17

As the atomic number increases the ratio of neutrons to protons in stable nuclei
A. becomes increasing greater than one
B. becomes increasingly closer to one
C. difficult to predict 
D. becomes increasingly less than one

Answer 17

A. becomes increasing greater than one

Question 18

Which type of radioactive decay is a precursor to annihilation radiation?
A. electron capture 
B. negatron emission
C. positron emission 
D. internal conversion

Answer 18

C. positron emission

Question 19

Iridium-192 has a half-life of 74.3 days. The average life of iridium-192 is

Answer 19

107 days

Question 20

What type of radioactive decay can be modelled as a neutron converting to a proton in the nucleus?
A. beta minus decay
B. beta plus decay
C. internal conversion
D. electron capture

Answer 20

A. beta minus decay

Question 21

For the nuclear reaction equation below, what is the Atomic Mass Number, A, for Polonium, Po?

Note: the Atomic Number of Pb is 82.

204Pb(α,n)APo

Answer 21

207

Question 22

For the nuclear reaction equation below, what is the Atomic Number, Z, for Polonium, Po?

Note: the Atomic Number of Pb is 82.

204Pb(α,γ)APo

Answer 22

84

Question 23

The primary purpose of the glass envelope of an x-ray tube is
A. attenuate scatter x-rays
B. direct the elctron to the anode
C. prevent electron leakage from the tube
D. to maintain a vacuum

Answer 23

D. to maintain a vacuum

Question 24

Tungsten is a good x-ray target due to
A. high atomic number
B. the high melting point
C. high x-ray production 
D. all answers are correct

Answer 24

D. all answers are correct

Question 25

The function of the voltage rectifier for an x-ray tube is to A. increase the x-ray output for the same input energy. B. increase the average energy of the x-rays. C. prevent electrons from traveling from anode to cathode. D. all answers are correct

Answer 25

D. all answers are correct

Question 26

Which is true of bremsstrahlung radiation? A. The production efficiency is inversely related to the voltage. B. The process is very efficient, producing very little heat. C. The production efficiency is directly related to the square of the tube voltage. D. The probability of production increases with the square of the atomic number.

Answer 26

D. The probability of production increases with the square of the atomic number.

Question 27

``` Which of the following type of generator has the lowest efficiency? A. single phase B. three phase C. high frequency D. constant potential ```

Answer 27

A. single phase

Question 28

T/F: In an x-ray tube the high voltage circuit causes the x-rays to travel from the cathode to the anode.

Answer 28

false

Question 29

Anodes are often made of copper because A. copper is efficient at creating x-rays. B. copper performs as a good heat sink. C. copper provides good attenuation of the electrons. D.copper is the preferred tubing for the cooling water.

Answer 29

B. copper performs as a good heat sink.

Question 30

Why are diodes used in a voltage rectification circuit? A. They hold the charge of voltage during the inverse of the waveform. B. They block AC currrent from the anode C. They increase the voltage across the x-ray tube D. They only allow current to flow in one direction

Answer 30

D. They only allow current to flow in one direction

Question 31

``` Which of the x-ray generators below use simultaneous input waveforms with shifted phases? A. constant potential B. three phase C. high frequency D. single phase ```

Answer 31

B. three phase

Question 32

Which is true of bremsstrahlung radiation? A. It is the primary source of x-rays from an x-ray tube. B. It is caused by the interaction of coulomb forces. C. The resultant x-ray can be of varying energies. D. All of the answers are true

Answer 32

D. All of the answers are true

Question 33

``` The efficiency of bremsstrahlung production for an x-ray target increases with a decrease in A. energy B. atomic number C. both answers are correct D. neither of the answers is correct ```

Answer 33

D. neither of the answers is correct

Question 34

Which is true about a cyclotron? A. It accelerates charged particles B. It is a source of protons or neutrons for treatment C. It can be used to produce radionuclides for nuclear medicine procedures D. All of the answers are correct

Answer 34

D. All of the answers are correct

Question 35

``` Which of the following is a disadvantage of a Cobalt-60 teletherapy machine? A. Complexity of machine B. Energy of the radiation output C. Lower treatment output D. High initial cost of purchase ```

Answer 35

C. Lower treatment output

Question 36

``` What is the advantage of the Bragg Peak? A. More penetrating than x-rays B. Delivers more dose at depth than at the surface C. Has an unlimited depth of treatment D. All of the answers are correct. ```

Answer 36

B. Delivers more dose at depth than at the surface

Question 37

``` Which parameter of the treatment beam determines the depth of the Bragg Peak? A. field size B. energy C. output D.none of the answers are correct ```

Answer 37

B. energy

Question 38

``` Which low energy treatment machine is commonly used to treat the surgical cavity after breast lumpectomy? A. Cyberknife B.Grenz-ray machine C. Gamma Knife D. Intrabeam E. Tomotherapy ```

Answer 38

D. Intrabeam

Question 39

``` Which component of a linear accelerator injects the electrons into the accelerating tube? A. modulator B. magnetron C. klystron D. electron gun ```

Answer 39

D. electron gun

Question 40

``` Which radiotherapy treatment machine accelerates electrons in a circle using two D-shaped segments? A. Betatron B. Superficial therapy machine C. Linear accelerator D. Cyclotron E. Grenz-ray machine ```

Answer 40

D. Cyclotron

Question 41

``` Which radiotherapy treatment machine operates at the lowest potential? A. Betatron B. Van de Graaff generator C. Grenz-ray machine D. Linear accelerator E. Superficial therapy machine ```

Answer 41

C. Grenz-ray machine

Question 42

``` Which component of a linear accelerator is used to transmit microwaves to the accelerating tube? A. modulator B. waveguide C. magnetron D. klystron ```

Answer 42

B. waveguide

Question 43

Which is the correct order of the beam path for electron treatment in a linear accelerator? A. Primary collimator, scattering foil, secondary collimator, ionization chamber B. Scattering foil, primary collimator, ionization chamber, secondary collimator C. Primary collimator, ionization chamber, scattering foil, secondary collimator D. Primary collimator, scattering foil, ionization chamber, secondary collimator

Answer 43

D. Primary collimator, scattering foil, ionization chamber, secondary collimator

Question 44

Calculate the penumbra for Source size = 0.2 cm, SDD = 65 cm, SSD = 100 cm, d = 10 cm Give your answer in millimeters to one decimal place.

Answer 44

1.3-1.4