Honors Chemistry Quiz: Unit 9 Nuclear Chemistry
Name: ______Period : ____ Date: ______This quiz is worth 40 points. Only those quizzes completed in black ink will be graded. (Interesting information: mass of a proton = 1.007825 amu and the mass of a neutron = 1.008665 amu.)
1. Alpha particles are identical to a. Protons b. Helium atoms c. Hydrogen atoms d. Helium nuclei e. Electrons
2. In the movie, “Fat Man, Little Boy,” Michael Merryman was exposed to 1000 rad of radiation from plutonium, an alpha emitter. How many sieverts does this exposure represent? a. 1000 Sv b. 2000 Sv c. 20,000 Sv d. 2 X 106 Sv e. 200 Sv
25 3. Calculate the binding energy per nucleon, in joules, for 12Mg (atomic mass = 23.985839 amu). a. 1.82 X 10-10J/nucleon b. 0.22076 J/nucleon c. 3.30 X 10-11 J/nucleon d. 0.999 J/nucleon e. None of the above.
4. When atoms of aluminum – 27 are bombarded with alpha particles, a neutron and an element are produced. The isotope formed is 31 a. 14Si 30 b. 14Si 31 c. 16S 30 d. 15P 31 e. 15P
1 5. The belt of stability indicates
a. An area of a graph of the number of protons vs. number of neutrons where the n/p ratio of all isotopes is 1.
b. An area of a graph of the number of protons vs. the number of neutrons where a beta particle emission occurs.
c. An area on a graph of the number of protons vs. the number of neutrons where the n/p ratio is 1 for nuclei with Z ≤20.
d. Nothing of importance for predicting stable nuclei.
e. Odd numbers of nucleons are always stable.
6. From the movie, “Fat Man, Little Boy,” where was the plutonium for one of the bombs produced?
a. Los Alamos
b. Oak Ridge
c. UCLA
d. New York
e. UC Berkley
7. Which of the following is true?
a. Nuclei that contain 2, 8, 20, 50, 82, or 126 protons or neutrons are more stable than those nuclei that do not have these numbers.
b. Nuclei with even numbers of both protons and neutrons are generally more stable than those that have odd numbers of these particles.
c. All isotopes of elements with atomic numbers higher that 83 are radioactive.
d. All isotopes of Tc and Pm are radioactive.
e. All of the above.
2 232 8. In the 90Th decay series, there are six radioisotopes that decay by alpha emission including Th-232 itself, and four radioisotopes that decay by beta emission. The final product of this series is a stable isotope. The symbol for this product is
a. 204 82Pb
b. 208 82Pb
c. 208 78Pt
d. 208 74W
e. 204 74W
9. 1 Joule equals
a. 1 kg m
b. 1 g m2 s2
c. 1 kg m2/s
d. 1 kg m2/s2
e. 1 g m2/s
10.Carbon-11 is a radioactive isotope of carbon. Its half-life is 20.3 minutes. Approximately, what fraction of the initial number of C-11 atoms in a sample will remain after 81 minutes?
a. 1/16
b. ¼
c. ½
d. 1/32
e. 1/64
3 11.Approximately, what is the average human’s exposure level to radiation each year (mrem)?
a. 500
b. 1000
c. 150
d. 2000
e. 750
12.Po-208 is an alpha emitter with a half-live of 2.90 years. How many mg of polonium from an original sample of 2.0 mg will remain after 8.0 years?
a. 0.147 mg
b. 0.295 mg
c. 0.725 mg
d. 6.77 mg
e. 1.90 mg
13.The 14C activity of some ancient Peruvian corn was found to be 10 disintegrations per minute per gram of carbon. If present-day plant
4 life shows 15 dpm/g, how old is the Peruvian corn? The half-life of 14C is 5730 years.
a. 1455 yr.
b. 1910 yr.
c. 3350 yr.
d. 3820 yr.
e. 9080 yr.
14.Critical mass can be defined as
a. Mass critical to start a nuclear reaction.
b. Mass necessary to detect radiation.
c. Mass necessary to avoid an atomic explosion.
d. Mass required to generate a self-sustaining nuclear reaction.
e. None of the above.
15.Which of the following are elementary particles involved in radioactive decay?
a. Alpha particle
b. Neutron
c. Positron
d. Proton
e. All the above
16.A sample of a radioisotope shows an activity of 999 disintegrations per minute due to beta decay. If after 1.1 years the activity is 952 disintegrations per minute, what is the half-life of this radioisotope?
a. 4.38 X 10-2 yr.
5 b. 11.4 yr.
c. 0.25 yr.
d. 15.8 yr.
e. 9.1 yr.
17.From the movie, “Fat Man, Little Boy,” the test sight for the first atomic bomb explosion is called
a. Los Alamos
b. Trinity
c. Oak Ridge
d. Manhattan
e. None of the above
18.Referring to the belt of stability, radioactive nuclei with N/P ratios above the belt go through a beta-particle emission. This emission represents
a. The conversion of a proton to a neutron.
b. The conversion of an alpha particle to a beta particle.
c. The conversion of U-235 to Pb-208.
d. The conversion of a neutron to a proton.
e. None of the above
6 19. Radioactive decay can be defined as
a. The formation of new elements by bombarding the nucleus of an element with subatomic particles.
b. Process where a heavy nucleus divides to form smaller nuclei of intermediate mass.
c. Combining of nuclei into larger ones.
d. Reaction occurring in the hydrogen bomb.
e. The disintegration of a radioactive nucleus in a sequence of nuclear reactions that ultimately yields a stable isotope.
20.The energy released by the sun is the result of
a. Natural radioactivity
b. Nuclear fusion
c. Combustion of hydrogen
d. Photosynthesis
e. Nuclear fission
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