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Chapter 02: Radiation Physics
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Iannucci: Dental Radiography, 6th Edition
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MULTIPLE CHOICE b
1. The fundamental unit of matter is the
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a. proton.
b. neutron.
c. electron.
d. atom.
ANS: D b
A proton is a subatomic particle. A neutron is a subatomic particle. An electron is a subatom
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icparticle. The fundamental unit of matter is the atom.
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DIF: Recall REF: Page 7 OBJ: 1 b b
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
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MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
2. The nucleus of an atom contains
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a. protons.
b. neutrons.
c. protons and neutrons. b b
d. electrons.
ANS: C b
The nucleus of an atom contains neutrons as well as protons. The nucleus of an atom contai
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nsprotons as well as neutrons. The nucleus of an atom contains protons and neutrons. The n
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ucleus of an atom does not contain electrons; it contains protons and neutrons.
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DIF: Recall REF: Page 7 OBJ: 2 b b
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
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MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
3. Which subatomic particle carries a negative electrical charge?
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a. A neutron b
b. A proton b
c. An electron b
d. A nucleon b
ANS: C b
A neutron does not carry an electrical charge. A proton carries a positive electrical charge.
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Anelectron carries a negative electrical charge. A nucleon carries a positive (proton) or no (
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neutron) electrical charge.
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DIF: Comprehension REF: Page 7 b
OBJ: 2TOP: CDA, RHS, III.B.2. Describe the characteristics of x
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-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
mynursytest.store
,DOWNLOADTHETestBankforDentalRadiography6thEditionIannucci
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4. Which of the following elements is the simplest atom?
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a. Hydrogen (H #1) b b
b. Helium (He #2) b b
c. Nitrogen (N #7) b b
d. Oxygen (O #8) b b
ANS: A b
Atomic numbers are assigned from simplest to most complex. Hydrogen is the simplest ato m;with
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a single proton, it has an atomic numbercof 1. Helium has an atomic number of 2. Nitrogen has an
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atomic number of 7. Oxygen has an atomic number of 8.
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DIF: Comprehension REF: Page 7 b
OBJ: 2TOP: CDA, RHS, III.B.2. Describe the characteristics of x
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-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
5. Which of the following statements is true of orbits or shells in the atom?
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a. Protons travel around the nucleus in well-defined shells. b b b b b b b
b. An atom contains innumerable shells.
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c. The energy level within each shell is the same.
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d. The orbiting shell closest to the nucleus has the highest energyclevel.
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ANS: D b
Electrons travel around the nucleus in well- b b b b b b
defined shells. An atom contains a maximum of seven shells. Each of the maximum seven shells
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within an atom represents a different energylevel. The orbiting shell closest to the nu cleus has the
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highest energy level. The K shell is theorbiting shell closest to the nucleus.
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DIF: Comprehension REF: Page 7 b
OBJ: 2TOP: CDA, RHS, III.B.2. Describe the characteristics of x
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-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
6. The binding energy or binding force of an electron is
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a. determined by the distance between the neutrons and protons within the nucleus. b b b b b b b b b b b
b. determined by the distance between the orbiting electrons and the nucleus. b b b b b b b b b b
c. weakercfor electrons located in inner shells than in outer shells. b b b b b b b b b
d. determined by the atomic number. b b b b
ANS: B b
The binding energy orcbinding force of an electron is not determined by the distance betwee n the
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neutrons and protons within the nucleus. The binding energy orcbinding force of an el ectron is
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determined by the distance between the nucleus and the orbiting electrons and is di fferent
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forceach shell. The binding energy orcbinding force of an electron is stronger forcelec trons
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located in inner shells than for outer shells. The binding energy is not determined byth e atomic
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number.
b
DIF: Recall REF: Page 7 OBJ: 2 TOP: CDA, N/A b b b
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
mynursytest.store
, DOWNLOADTHETestBankforDentalRadiography6thEditionIannucci
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7. Which of the following statements is true of ionization?
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a. An atom that gains an electron will have a negative charge.
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b. An atom that loses an electron will have a negative charge.
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c. An atom that loses an electron will have a positive charge.
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d. An atom that gains an electron has a negative charge, and an atom that loses
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anelectron has a positive charge.
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ANS: D b
This answer is not the best answer. An atom that gains an electron has a negative charge; h
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owever, an atom that loses an electron has a positive charge. An atom that loses an electron will
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have a positive charge. An atom that loses an electron has a positive charge; however, anatom that
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gains an electron has a negative charge. An atom that gains an electron will ha ve a negative
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charge, and an atom that loses an electron will have a positive charge. An ato m that gains
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orcloses an electron and becomes electrically unbalanced is known as an ion.
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DIF: Comprehension REF: Page 9 b
OBJ: 3TOP: CDA, N/A b b b b
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
8. An ion paircresults when
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a. a proton is removed from an atom.
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b. an electron is removed from an atom.
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c. a neutron is removed from an atom.
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d. two atoms share a pair of electrons. b b b b b b
ANS: B b
An ion pair results when an electron is removed from an atom rather than a proton. When
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anelectron is removed from an atom in the ionization process, an ion pair results. The ato m
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becomes the positive ion, and the ejected electron becomes the negative ion. An ion pai r
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results when an electron is removed from an atom rathercthan a neutron. A molecule occ urs
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when two atoms share a pair of electrons.
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DIF: Recall REF: Page 9 OBJ: 3 b b
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
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MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of Radiophysic sand
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Radiobiology
b
9. (1) Radiation is the emission and propagation of energy through space or a substance in the form
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of waves or particles. (2) Radioactivity can be defined as the process by which certain unstable
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atoms orcelements undergo spontaneous disintegration, or decay, in an effort to atta ina more
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balanced nuclearcstate.
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a. Both statements are true. b b b
b. Both statements are false. b b b
c. The first statement is true; the second statement is false.
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d. The first statement is false; the second statement is true.
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ANS: A b
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