# Final Examination Time

The final examination time for SCI270 has been scheduled by the Registrar to be April 7, 2004, 19:00-22:00, in the PAC Area 1 and 2.

Please double-check it out from the UoW website.

The final exam consists of many multiple choice questions. The exact number of question has not been finalized yet. I will certainly concentrate on materials mentioned during lectures, but study all the material in the lecture notes please.

All chapters in the lecture notes will be included for the final exam.

## Some Example Questions of the Final Examination

No answer is or will be provided here for the following example questions. Please use these for checking your ability or skills rather than trying to catch the questions during the final exam. At least, I am trying to avoid the same questions.

### Data

 Data for 14C: half life, 5730 y; mode of decay, beta; decay energy, 0.156 MeV Masses (amu): 1H, 1.007825; 1n: 1.008665; 2D, 2.0140; 3T, 3.01605; 4He, 4.00260; 14N, 14.00307; 24Mg12, 23.98504; 64Ni28, 63.9280; 64Zn30, 63.9291. Constants: Avogadro's number = 6.022x1023 mol-1; 1.0 y = 31558152 s; 1.0 Ci = 3.700x1010 Bq; Charge per electron = 1.6029x10-19 C; Faraday constant = 96485 C; Conversion factors: 1 amu = 1.66053x10-27 kg = 1.4924x10-10 J = 931.4812 MeV.

 For 59Co27: atomic mass = 58.9332 amu, abundance = 100%; the total cross sections for the reaction 59Co (n, gamma) 60Co reaction = 37 b. For 60Co, half life = 5.26 y, decay energy = 2.819 MeV. For 60Ni28, atomic mass = 59.9307906 amu, abundance = 26.23%.

•  Equation 1: ________________________ Decay energy ________ Equation 2: ________________________ Decay energy ________ Equation 1: ________________________ Decay energy ________
The nuclide 64Cu29 (Z = 29) is known to have all three modes of beta decay. The overall half life is 12.9 h. The atomic masses (amu) are: 64Ni28, 63.9280; 64Zn30, 63.9291.

Write the three decay equations to show the three modes of decays, and give the energy for each decay.

• Which of the following detectors is the best for the measurement of the gamma-ray spectrum from a source?
1. bubble and cloud chambers
2. proportional counters
3. Geiger counters
4. photographic emulsions and films
5. solid state detectors

• What is the major reason for CANDU (CANadian Deuterium Uranium) reactors to use heavy water as the moderator?
1. Heavy water is more effective to slow down the fast moving neutrons than ordinary water.
2. Deuterium atoms capture neutrons to produce tritium atoms.
3. Only heavy water moderated reactors produce tritium atoms.
4. Deuterium atoms have smaller thermal-neutron-capture cross sections than hydrogen atoms. reaction.
5. Heavy water removes unwanted neutrons from the reactor core quickly.

• What are force carriers (also called gauge bosons) of the electromagnetic force?
1. electrons
2. photons
3. neutrinos
4. gluons
5. gravitons

• Rubidium 87, 87Rb37 is a natural radioactive nuclide with a half life of 4.9x1010 y, and the decay energy is 0.273 MeV. Which statement correctly describes the energy spectrum of beta particles emitted by 87Rb37?
1. All beta particles have a kinetic energy of 0.273 MeV.
2. The average kinetic energy of the beta particle is 0.273 MeV.
3. The kinetic energy of the majority of beta particles is 0.273 MeV
4. The number of beta particles having 0.273 MeV kinetic energy is the highest.
5. Kinetic energies of the beta particles range from 0 to a maximum of 0.273 MeV.

• Which statement describes the most important feature of fast breeder reactors?
1. Fast breeder reactors are used to enrich 235U as reactor fuel.
2. Fast breeder reactors produce more 235U than they consume.
3. Fast breeder reactors need no moderators.
4. Fast breeder reactors produce fusion fuel 3T.
5. Fast breeder reactors operate at higher temperature to produce fission fuel 239Pu.

• Which one of the following is emitted by a hot solid?
1. A line spectrum with sets of lights of some special wavelengths.
2. A continuous or white spectrum with some dark lines. Light of certain frequencies are missing.
3. A continuous or white spectrum containing electromagnetic radiation of a range of frequencies.
4. Electromagnetic radiation of a definite wavelength.
5. A laser beam.

• What is the rate of disintegration from a sample that contains 1.0 g of 60Co atoms?
1. 1.91x1016 Bq
2. 3.18x1014 Bq
3. 1.91x1016 Ci
4. 3.18x1014 Ci
5. 4.18x1013 Bq