, Chapter 01: Radiation Physics
MULTIPLE CHOICE
1. The fundamental unit of matter is the
a. proton.
b. neutron.
c. electron.
d. atom.
ANS: D
A proton is a subatomic particle; the fundamental unit of matter is the atom. A neutron is
a subatomic particle; the fundamental unit of matter is the atom. An electron is a
subatomic particle; the fundamental unit of matter is the atom. The fundamental unit of
matter is the atom.
DIF: Recall REF: Page 8 OBJ: 1
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
2. The nucleus of an atom contains
a. protons.
b. neutrons.
c. protons and neutrons.
d. electrons.
ANS: C
The nucleus of an atom contains neutrons as well as protons. The nucleus of an atom
contains protons as well as neutrons. The nucleus of an atom contains protons and
neutrons. The nucleus of an atom does not contain electrons; it contains protons and
neutrons.
DIF: Recall REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
, 3. Which subatomic particle carries a negative electrical charge?
a. A neutron
b. A proton
c. An electron
d. A nucleon
ANS: C
A neutron does not carry an electrical charge. A proton carries a positive electrical charge.
An electron carries a negative electrical charge. A nucleon carries a positive (proton) or
no (neutron) electrical charge.
DIF: Comprehension REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
4. Which of the following elements is the simplest atom?
a. Hydrogen (H #1)
b. Helium (He #2)
c. Nitrogen (N #7)
d. Oxygen (O #8)
ANS: A
Atomic numbers are assigned from simplest to most complex. Hydrogen is the simplest
atom; with a single proton, it has an atomic number of 1. Helium has an atomic number
of 2. Nitrogen has an atomic number of 7. Oxygen has an atomic number of 8.
DIF: Comprehension REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles ofradiophysics and radiobiology
, 5. Which of the following statements is true of orbits or shells in the atom?
a. Protons travel around the nucleus in well-
defined shells.
b. An atom contains innumerable shells.
c. The energy level within each shell is the
same.
d. The orbiting shell closest to the nucleus
has the highest energy level.
ANS: D
Electrons travel around the nucleus in well-defined shells. An atom contains a maximum
of seven shells. Each of the maximum seven shells within an atom represents a different
energy level. The orbiting shell closest to the nucleus has the highest energy level. The K
shell is the orbiting shell closest to the nucleus.
DIF: Comprehension REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
6. The binding energy or binding force of an electron is
a. determined by the distance between the
neutrons and protons within the nucleus.
b. determined by the distance between the
orbiting electrons and the nucleus.
c. weaker for electrons located in inner
shells than in outer shells.
d. determined by the atomic number.
ANS: B
The binding energy or binding force of an electron is determined by the distance between
the nucleus and the orbiting electron. The binding energy or binding force of an electron
is determined by the distance between the orbiting electron and the nucleus, not the
distance between the orbiting electrons. The binding energy or binding force of an
electron is stronger for electrons located in inner shells than for outer shells.
DIF: Recall REF: Page 8 OBJ: 2 TOP: CDA, N/A
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles ofradiophysics and radiobiology
MULTIPLE CHOICE
1. The fundamental unit of matter is the
a. proton.
b. neutron.
c. electron.
d. atom.
ANS: D
A proton is a subatomic particle; the fundamental unit of matter is the atom. A neutron is
a subatomic particle; the fundamental unit of matter is the atom. An electron is a
subatomic particle; the fundamental unit of matter is the atom. The fundamental unit of
matter is the atom.
DIF: Recall REF: Page 8 OBJ: 1
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
2. The nucleus of an atom contains
a. protons.
b. neutrons.
c. protons and neutrons.
d. electrons.
ANS: C
The nucleus of an atom contains neutrons as well as protons. The nucleus of an atom
contains protons as well as neutrons. The nucleus of an atom contains protons and
neutrons. The nucleus of an atom does not contain electrons; it contains protons and
neutrons.
DIF: Recall REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
, 3. Which subatomic particle carries a negative electrical charge?
a. A neutron
b. A proton
c. An electron
d. A nucleon
ANS: C
A neutron does not carry an electrical charge. A proton carries a positive electrical charge.
An electron carries a negative electrical charge. A nucleon carries a positive (proton) or
no (neutron) electrical charge.
DIF: Comprehension REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
4. Which of the following elements is the simplest atom?
a. Hydrogen (H #1)
b. Helium (He #2)
c. Nitrogen (N #7)
d. Oxygen (O #8)
ANS: A
Atomic numbers are assigned from simplest to most complex. Hydrogen is the simplest
atom; with a single proton, it has an atomic number of 1. Helium has an atomic number
of 2. Nitrogen has an atomic number of 7. Oxygen has an atomic number of 8.
DIF: Comprehension REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles ofradiophysics and radiobiology
, 5. Which of the following statements is true of orbits or shells in the atom?
a. Protons travel around the nucleus in well-
defined shells.
b. An atom contains innumerable shells.
c. The energy level within each shell is the
same.
d. The orbiting shell closest to the nucleus
has the highest energy level.
ANS: D
Electrons travel around the nucleus in well-defined shells. An atom contains a maximum
of seven shells. Each of the maximum seven shells within an atom represents a different
energy level. The orbiting shell closest to the nucleus has the highest energy level. The K
shell is the orbiting shell closest to the nucleus.
DIF: Comprehension REF: Page 8 OBJ: 2
TOP: CDA, RHS, III.B.2. Describe the characteristics of x-radiation
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles of
radiophysics and radiobiology
6. The binding energy or binding force of an electron is
a. determined by the distance between the
neutrons and protons within the nucleus.
b. determined by the distance between the
orbiting electrons and the nucleus.
c. weaker for electrons located in inner
shells than in outer shells.
d. determined by the atomic number.
ANS: B
The binding energy or binding force of an electron is determined by the distance between
the nucleus and the orbiting electron. The binding energy or binding force of an electron
is determined by the distance between the orbiting electron and the nucleus, not the
distance between the orbiting electrons. The binding energy or binding force of an
electron is stronger for electrons located in inner shells than for outer shells.
DIF: Recall REF: Page 8 OBJ: 2 TOP: CDA, N/A
MSC: NBDHE, 2.0 Obtaining and Interpreting Radiographs | NBDHE, 2.1 Principles ofradiophysics and radiobiology
