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1 | |
The diameter of an atom is approximately 10,000 times the diameter of its nucleus. |
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| | A) | True |
| | B) | False |
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2 | |
The difference between the mass number of an isotope and its atomic number is equal to the number of nucleons in the nucleus. |
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| | A) | True |
| | B) | False |
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3 | |
An element may have more than one mass number, but the mass number for a stable isotope is fixed. |
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| | A) | True |
| | B) | False |
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4 | |
The radioactive half-life of a substance is one-half of the time required for all the unstable atoms in that substance to decay. |
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| | A) | True |
| | B) | False |
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5 | |
In alpha decay, the mass number of an unstable isotope is reduced by 4 and the atomic number is reduced by 2. |
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| | A) | True |
| | B) | False |
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6 | |
The binding energy of an element is equivalent to the product of the mass defect and the square of the velocity of light. |
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| | A) | True |
| | B) | False |
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7 | |
In a balanced nuclear equation, the sum of the atomic numbers and the sum of the mass numbers must be the same on both sides of the nuclear equation. |
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| | A) | True |
| | B) | False |
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8 | |
In nuclear fission energy is emitted, whereas in nuclear fusion energy is absorbed. |
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| | A) | True |
| | B) | False |
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9 | |
The function of the moderator in a nuclear reactor is to slow down the nuclear fission process and thereby control the release of energy. |
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| | A) | True |
| | B) | False |
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10 | |
Isotopes are atoms that have the same |
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| | A) | number of neutrons |
| | B) | atomic number |
| | C) | number of nucleons |
| | D) | atomic mass |
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11 | |
The process by which a nucleus with a large mass number splits into lighter nuclei is called |
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| | A) | fission |
| | B) | fusion |
| | C) | alpha decay |
| | D) | beta decay |
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12 | |
In the mass spectrometer, the distance from the slit to the impact on the plate is 10 cm for isotope A and 12 cm for isotope B. The ratio of their masses MA/MB is approximately |
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| | A) | 0.83 |
| | B) | 0.93 |
| | C) | 1.2 |
| | D) | 1.33 |
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13 | |
If two light nuclei are fused in a nuclear reaction, the average energy per nucleon |
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| | A) | increases |
| | B) | remains the same |
| | C) | decreases |
| | D) | cannot be determined |
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14 | |
A sample of radioactive material contains N radioactive nuclei at a given instant. If the half-life is 20 s, how many unstable nuclei remain after 1 h? |
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| | A) | N/2 |
| | B) | N/4 |
| | C) | N/6 |
| | D) | N/8 |
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15 | |
When a beta-plus particle encounters an electron, they cancel each other and both disappear. This annihilation of matter produces two photons, each having an energy of approximately |
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| | A) | 0.466 MeV |
| | B) | 0.511 MeV |
| | C) | 0.931 MeV |
| | D) | 1.02 MeV |
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16 | |
A deuteron is a particle consisting of a neutron and a proton bound together by nuclear forces. If the rest mass of a deuteron is 3.34313 x 10-27 kg, the binding energy is approximately |
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| | A) | 2.22 MeV |
| | B) | 3.11 MeV |
| | C) | 4.44 MeV |
| | D) | 6.22 MeV |
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17 | |
In a nuclear reactor, which of the following is used to slow down the fast neutrons released in the fission process? |
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| | A) | Moderator |
| | B) | Control rods |
| | C) | Radiation shielding |
| | D) | Heat exchanger |
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18 | |
In general, the is defined as the energy required to break up a nucleus into its constituent protons and neutrons. |
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19 | |
The half-life for alpha decay for deuterium is 10.2 s. One-fourth of the unstable atoms will remain after s. |
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20 | |
An activity of is equal to 3.7 x 1010 disintegrations per second. |
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21 | |
The is the total number of nucleons in the nucleus. It can be computed by adding the number of to the number of . |
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22 | |
Basic components of a nuclear reactor are , , , ,
and . |
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23 | |
In a nuclear fission, the fission fragments have a(n) mass number and hence a(n) binding energy per nucleon. |
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24 | |
Isotopes are atoms that have the same but different . |
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25 | |
A mass defect of 1 u is equivalent to an energy of . |
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26 | |
Three quantities that must be conserved in a nuclear reaction are , , and . |
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