RADIATION SAFETY EXAM Q&A
2024/2025
Which of the following is a pure substance that cannot be broken down into simpler
substances by chemical means? - Answer-Element
Which of the following has no charge? - Answer-Gamma Ray
The smallest unit of a compound that still retains the unique physical and chemical
characteristics of the compound is a? - Answer-Molecule
Which of the following is a substance composed of different elements bound in fixed
proportions? - Answer-Compound
Which of the following is the smallest unit of a compound still retaining its unique
physical and chemical characteristics? - Answer-Molecule
Which of these is a characteristic of an atom? - Answer-A single central nucleus
z=1 proton
z=6 protons
z=26 protons
also known as atomic number (z) - Answer-Hydrogen
Carbon
Iron
What is the atomic mass number? - Answer-The sum of protons and neutrons in an
atom
What is the atomic mass of this lithium atom? - Answer-6
Refer to the Periodic Table of Elements to identify an element with an atomic number of
eighty-eight (88). - Answer-Ra
What configuration defines an isotope? - Answer-The same number of protons but a
different number of neutrons
Given that protons are red and neutrons are blue, which two of the four graphics
pictured are isotopes of the same element? - Answer-2 and 3 are isotopes
Which isotope of hydrogen is unstable? - Answer-Tritium | H-3
How is nuclear (radioactive) decay defined? - Answer-An unstable nucleus releasing
energy
,Which statement best describes a daughter product of nuclear decay? - Answer-It can
be stable or unstable but will always have less energy than its parent.
A half-life is the time it takes a radioactive isotope to transform 50 percent of its atoms
by radioactive decay. - Answer-H-3 = Tritium has a half-life of 12.3 years.
AM-241 = Americium-241 has a half-life of 458 years.
U-238 = Uranium-238 has a half-life of 4.5 billion years.
I-131 = Iodine-131 has a half-life of 8 days.
Ni-63 = Nickel-63 has a half-life of 92 years.
What is the half-life of an unstable isotope? - Answer-The time required for half of its
atoms to decay
How much of the parent isotope remains after two half-lives of decay? - Answer-.25 or
1/4
Why are alpha particles, beta particles, and gamma rays considered forms of nuclear
radiation? - Answer-All three originate in the nucleus.
What charge does an alpha particle contain? - Answer-+2 (positive two) charge
Which statement is true about alpha particles? - Answer-They have two neutrons.
What charge does a beta particle contain? - Answer--1 (negative one) charge
Which statement is true about beta particles? - Answer-They have the same mass as
an electron.
What charge does a gamma ray contain? - Answer-No charge at all
Which statement is true about gamma rays? - Answer-They move at the speed of light.
Which is the fastest moving? - Answer-Gamma ray
Which atom is an ion? - Answer-Protium
An ion will always carry either a positive charge or a negative charge. - Answer-True
What is the process of a neutral atom acquiring either a positive or negative charge? -
Answer-Ionization
, What is ionization? - Answer-The process of a neutral atom acquiring either a positive
or negative charge
What is ionization? Select and submit your response. - Answer-The process of a neutral
atom acquiring either a positive or negative charge
Ions behave the same as their neutral forms. - Answer-True
How are X-rays and gamma rays alike?Select all that apply. - Answer-o They are
ionizing forms of radiation.
x They have the same properties of range, ionization, and penetration.
Gama Rays - Answer-Created inside the nucleus
Form of nuclear radiation
X-Rays - Answer-Created outside the nucleus
Form of non-nuclear radiation
Millicurie (mCI) = 37,000,000 dps
Microcuri (µCi) = 37,000 dps
Nanocurie (nCI) = 37 dps - Answer-10 -3
10 -6
10 -9
What is the special unit for activity called? - Answer-Curie
"µCi" is the abbreviation for which unit of measure? - Answer-Microcurie
Kiloelectron Volts (keV)
1 keV = - Answer-= 1000 electron volts
1000 eV
megaelectron volts (MeV)
1 Mev = - Answer-1000000 electron volts
1000000 ev
What is the special unit for the energy level of ionizing radiation called? - Answer-
Electron volt
Which of the following is equal to 1,000 electron volts? - Answer-keV
What indicates the energy levels for gamma rays and X-rays? - Answer-Frequency
One roentgen of exposure produces 2.08 billion ion pairs per cubic centimeter of dry air.
- Answer-The Roentgen (R) = 2.58 X 10-4 coulombs/kilograms of air
2024/2025
Which of the following is a pure substance that cannot be broken down into simpler
substances by chemical means? - Answer-Element
Which of the following has no charge? - Answer-Gamma Ray
The smallest unit of a compound that still retains the unique physical and chemical
characteristics of the compound is a? - Answer-Molecule
Which of the following is a substance composed of different elements bound in fixed
proportions? - Answer-Compound
Which of the following is the smallest unit of a compound still retaining its unique
physical and chemical characteristics? - Answer-Molecule
Which of these is a characteristic of an atom? - Answer-A single central nucleus
z=1 proton
z=6 protons
z=26 protons
also known as atomic number (z) - Answer-Hydrogen
Carbon
Iron
What is the atomic mass number? - Answer-The sum of protons and neutrons in an
atom
What is the atomic mass of this lithium atom? - Answer-6
Refer to the Periodic Table of Elements to identify an element with an atomic number of
eighty-eight (88). - Answer-Ra
What configuration defines an isotope? - Answer-The same number of protons but a
different number of neutrons
Given that protons are red and neutrons are blue, which two of the four graphics
pictured are isotopes of the same element? - Answer-2 and 3 are isotopes
Which isotope of hydrogen is unstable? - Answer-Tritium | H-3
How is nuclear (radioactive) decay defined? - Answer-An unstable nucleus releasing
energy
,Which statement best describes a daughter product of nuclear decay? - Answer-It can
be stable or unstable but will always have less energy than its parent.
A half-life is the time it takes a radioactive isotope to transform 50 percent of its atoms
by radioactive decay. - Answer-H-3 = Tritium has a half-life of 12.3 years.
AM-241 = Americium-241 has a half-life of 458 years.
U-238 = Uranium-238 has a half-life of 4.5 billion years.
I-131 = Iodine-131 has a half-life of 8 days.
Ni-63 = Nickel-63 has a half-life of 92 years.
What is the half-life of an unstable isotope? - Answer-The time required for half of its
atoms to decay
How much of the parent isotope remains after two half-lives of decay? - Answer-.25 or
1/4
Why are alpha particles, beta particles, and gamma rays considered forms of nuclear
radiation? - Answer-All three originate in the nucleus.
What charge does an alpha particle contain? - Answer-+2 (positive two) charge
Which statement is true about alpha particles? - Answer-They have two neutrons.
What charge does a beta particle contain? - Answer--1 (negative one) charge
Which statement is true about beta particles? - Answer-They have the same mass as
an electron.
What charge does a gamma ray contain? - Answer-No charge at all
Which statement is true about gamma rays? - Answer-They move at the speed of light.
Which is the fastest moving? - Answer-Gamma ray
Which atom is an ion? - Answer-Protium
An ion will always carry either a positive charge or a negative charge. - Answer-True
What is the process of a neutral atom acquiring either a positive or negative charge? -
Answer-Ionization
, What is ionization? - Answer-The process of a neutral atom acquiring either a positive
or negative charge
What is ionization? Select and submit your response. - Answer-The process of a neutral
atom acquiring either a positive or negative charge
Ions behave the same as their neutral forms. - Answer-True
How are X-rays and gamma rays alike?Select all that apply. - Answer-o They are
ionizing forms of radiation.
x They have the same properties of range, ionization, and penetration.
Gama Rays - Answer-Created inside the nucleus
Form of nuclear radiation
X-Rays - Answer-Created outside the nucleus
Form of non-nuclear radiation
Millicurie (mCI) = 37,000,000 dps
Microcuri (µCi) = 37,000 dps
Nanocurie (nCI) = 37 dps - Answer-10 -3
10 -6
10 -9
What is the special unit for activity called? - Answer-Curie
"µCi" is the abbreviation for which unit of measure? - Answer-Microcurie
Kiloelectron Volts (keV)
1 keV = - Answer-= 1000 electron volts
1000 eV
megaelectron volts (MeV)
1 Mev = - Answer-1000000 electron volts
1000000 ev
What is the special unit for the energy level of ionizing radiation called? - Answer-
Electron volt
Which of the following is equal to 1,000 electron volts? - Answer-keV
What indicates the energy levels for gamma rays and X-rays? - Answer-Frequency
One roentgen of exposure produces 2.08 billion ion pairs per cubic centimeter of dry air.
- Answer-The Roentgen (R) = 2.58 X 10-4 coulombs/kilograms of air
