Review

1. Modules 1-3 Review

2. Which of the following is not considered a force? • Electromagnetic • Weak • Strong • Gravity • Electricity • Electricity is the flow of charge in Coulombs / second.

3. Concerning beta-minus decay: • A. Beta particles are emitted with exactly the same energy for a given nucleus. • B. The parent and daughter nuclei have the same chemical properties. • C. There is a minimum energy of 1.02 MeV, which must be available for the decay to occur. • D. There is increase in proton-neutron ratio from parent to daughter. • E. It is always followed by the emission of characteristic radiation. • Beta-minus decay involves converting the extra neutron in the parent o a proton in the daughter and the emission of beta. The P/N in the parent will become will become P+1/N-1 in the daughter. This means an increase in the daughter atomic number, producing a new material with different chemical properties. Emitted beta particles will form a spectrum of energies from low to the maximum usually reported by the decay scheme. The 1.02 MeV threshold is applicable to beta-plus (positron) decay. Beta emission could be followed by the emission of gamma from some types of the decaying atoms, but not characteristic radiation, which is secondary to electron capture.

4. Which of the following is/are likely to have the longest wavelength? • Gamma rays • Microwaves • Radio waves • Ultraviolet • Visible light • Radio waves have lowest frequencies & longest wavelength.

5. The indirect effect resulting from exposure to low-LET radiation results from: • A. Ionizations produced within critical target molecules. • B. Auger electrons produced as part of the photoelectric effect. • C. Results in DNA damages that are generally reparable. • D. The formation of hydroxyl radicals produced by the radiolysis of water. • E. Irradiation only under hypoxic conditions. • The indirect effect involves the formation of hydroxyl radical produced by the radiolysis of water that react with critical cellular constituents, such as DNA, to create damages.

6. For electromagnetic radiation, which increases with increasing photon energy? • Wavelength • Frequency • Velocity • Charge • Mass • E = hf

7. Electrons passing through matter lose energy primarily by producing: • Bremsstrahlung • Characteristic x-rays • Atomic ionizations • Compton electrons • Photoelectrons • Electrons lose most of their kinetic energy by knocking out outer shell electrons

8. Which of the following refers to the number of nucleons in a nucleus? • Mass number • Atomic number • Avogadro’s number • Atomic mass unit • Nuclear density • Mass number = number of protons + neutrons (nucleons) in atomic nucleus.

9. The outer shell electrons most likely have binding energies (keV) of approximately: • 0.001 • 0.005 • 0.025 • 0.025 • 0.1 • 0.5 • BE outer shell electron ~ 5 eV

10. Ionizing radiations are least likely to include: • X-ray photons • Energetic electrons • Infrared radiation • Alpha particles • Fast neutrons • Infrared as photons energy < 1 eV

11. 15O and 16O are examples of: • Isotopes • Isotones • Isomers • Isobars • Metastable states • Isotopes since Z is unchanged.

12. Which of the following decay modes most likely changes the mass number (A) of an unstable nucleus? • Beta minus decay • Beta plus decay • Alpha decay • Isomeric transition • Electron Capture • Alpha decay will reduce the radionuclide atomic number by 2 & mass number by 4.

13. 60Co (Z=27) decaying to 60Ni (Z=28) is an example of: • β+ decay • β- decay • Electron capture • αDecay • Isomeric transition • Beta minus since the daughter’s atomic number increased by 1 by emitting β– particle.

14. Electron capture nuclei are most likely to produce: • Antineutrinos • Internal conversion electrons • Characteristic x-rays • β+ particles • β- particles • EC always results in characteristic x-rays since inner shell vacancy will be filled by an outer shell electron  characteristic x-ray emission.

15. A radionuclide produced in a nuclear reactor is most likely to decay by: • β- decay • β+ decay • Alpha decay • Isomeric transition • Electron capture • Radionuclides produced are neutron rich, therefore beta minus decay

16. All of the following are electromagnetic waves, except: • Heat • Radiation used in MRI • Sunlight • Sound • FM radio signals

17. If the wavelength of an x-ray is reduced by half, its frequency is: • Increased by 4 • Increased by 2 • Unchanged • Decreased to 0.5 • Decreased by 0.25 • c = fλ where c= speed of light (constant)