Introductory Chemistry, 5e (Tro)
Chapter 17 Radioactivity and Nuclear Chemistry
17.1 True/False Questions
1) Radioactivity is the emission of tiny, invisible radio signals by the nuclei of certain atoms.
2) Radioactive particles can pass through matter.
3) Antoine-Henri Becquerel discovered X-rays.
4) Madam Curie discovered two new elements.
5) F contains 11 protons and 9 neutrons.
6) The alpha particle (α) is: He.
7) When an atom emits an alpha particle, it becomes a different element.
8) Alpha particles have lower penetrating power than the other types of radioactive emissions..
9) A beta particle can also be called an electron.
10) During beta decay, neutrons are converted to protons and electrons.
11) When an atom emits a beta particle, its atomic number increases by one because it now has
one additional proton.
12) A gamma ray is a high energy photon.
13) A gamma ray has no charge and no mass.
14) The symbol for a positron is e.
15) A positron particle comes from the decay of a proton into a neutron and a positron.
16) Nuclear equations do not need to be balanced since a new element forms.
17) Radioactive elements become stable isotopes after emitting one of the radioactive particles
18) A nuclear reaction typically changes the identity of the element involved.
19) In a Geiger-Muller counter, radioactive particles pass through NaI which emits UV-Vis light.
20) All elements with atomic numbers above bismuth are naturally radioactive.
21) All unstable elements have the same rates of radioactive decay.
22) Nuclides that decay slowly have long half-lives.
23) A nuclide with a shorter half-life would be considered more active than a nuclide with a
longer half-life.
24) Phosphorous-32 has a half-life of 14.3 days while radon-222 has a half-life of 3.8 days, so
phosphorous-32 is considered more active.
25) During the first half-life you lose half of the radioactive material, during the second half life
you lose the remaining half.
26) Carbon-14 dating is based on the fact that C-14 is continuously being made in the upper
atmosphere.
27) C-14 dating has been verified using old iron ore samples of known age.
28) Carbon-14 dating is not dependable when attempting to date objects that are more than
50,000 years old.
29) Uranium-235 is capable of undergoing a fission chain reaction.
30) The effort to build an atomic bomb during WWII was prompted by a fear that Germany was
already working on nuclear weapons.
31) Nuclear power plants produce energy by fission reactions.
32) The reaction H + H → He + neutron is an example of nuclear fission.
33) One danger of a nuclear power plant is that a chain reaction could produce a bomb.
34) The hydrogen isotope known as tritium contains three neutrons.
35) The energy of the sun comes from fusion reactions.
36) The combination of two light nuclei to form a heavier one is known as nuclear fission.
37) A fusion reaction emits large amounts of energy while a fission reaction absorbs large
amounts of energy.
38) Nuclear fission reactions produce ten times more energy per gram than fusion reactions.
39) A major natural source of radiation is due to the radon gas in our environment.
40) Exposure to nuclear radioactivity can produce genetic defects in offspring.
41) One method of nuclear medicine uses radioactive isotopes to scan specific regions of the
body.
42) A patient having radiotherapy uses radioactivity to kill infected cells while trying to
minimize the effect on the healthy cells.
17.2 Multiple Choice Questions
1) Radioactive elements are used for:
A) medical diagnosis.
B) medical treatment.
C) determining age of fossils and rocks.
D) generating electricity.
E) all of the above
2) Who discovered radioactivity?
A) Antoine Becquerel
B) Pierre Curie
C) Marie Curie
D) Ernest Rutherford
E) Benjamin Franklin
3) How was radioactivity discovered?
A) Rutherford was investigating the structure of Au atoms and discovered alpha particles.
B) Marie Curie was investigating the existence of uranic rays that occurred in some minerals.
C) Becquerel was studying X-rays and phosphorescence to see if they were related.
D) Benjamin Franklin was studying the creation of electrical current from the ionization of gases
due to radioactive particles.
E) none of the above
4) During the career of Marie Curie, she:
A) won a Nobel prize in chemistry.
B) won a Nobel prize in physics.
C) discovered the element polonium.
D) discovered the element radium.
E) all of the above
5) Which of the following isotopes contains the most number of neutrons?
A) Rn
B) Bi
C) Fr
D) Po
E) Rn
6) How many protons and neutrons are in S?
A) 16 p and 34 n
B) 16 n and 34 p
C) 16 n and 18 p
D) 16 p and 18 n
E) none of the above
7) How many protons and neutrons are in U?
A) 92 p and 235 n
B) 92 n and 235 p
C) 92 n and 143 p
D) 92 p and 143 n
E) none of the above
8) How many protons and neutrons are in Sn?
A) 50 p and 169 n
B) 50 n and 69 p
C) 50 n and 119 p
D) 50 p and 69 n
E) none of the above
9) In a nuclear equation:
A) the daughter nuclide appears on the right-side of the arrow.
B) the sum of the atomic numbers on both sides must be equal.
C) the sum of the mass numbers on both sides must be equal.
D) all of the above
E) none of the above
10) Which statement about alpha particles is FALSE?
A) symbol is: He
B) has high ionization power
C) has low penetrating power
D) are a harmless form of radiation
E) All of the above are true.
11) The first experiment that converted one element to another was performed in 1919 by Ernest
Rutherford. An isotope of nitrogen was bombarded with a type of particle to get an oxygen atom
as shown:
N + ? → O + H
Which type of particle was used to bombard the nitrogen atom?
A) alpha
B) beta
C) positron
D) gamma
E) none of the above
12) If the Th isotope emits an alpha particle, what would be the atomic number of the
resulting atom?
A) 90
B) 88
C) 92
D) 228
E) 236
13) What happens to the mass number of a nucleus that emits an alpha particle?
A) It remains the same.
B) It decreases by two.
C) It decreases by four.
D) It increases by two.
E) It increases by four.
14) What is the main product when U undergoes alpha decay?
A) Am
B) Th
C) U
D) Th
E) none of the above
15) What is the missing particle?
A) positron
B) beta particle
C) alpha particle
D) gamma particle
E) none of the above
16) What is the missing particle?
A) positron
B) beta particle
C) alpha particle
D) gamma particle
E) none of the above
17) What is the main product when Pa undergoes alpha decay?
A) Pu
B) Ac
C) Ac
D) Ac
E) none of the above
18) Which of the following statements about beta particles is FALSE?
A) The symbol is: e.
B) Beta particles are created when neutrons become protons and electrons.
C) They have intermediate ionizing power.
D) They have intermediate penetrating power.
E) They are a safe form of radioactivity.
19) Which type of emission has a negative charge?
A) alpha
B) beta
C) positron
D) gamma
E) none of the above
20) What happens to the atomic number of a nucleus that emits a beta particle?
A) It remains the same.
B) It increases by one.
C) It decreases by one.
D) It increases by two.
E) It decreases by two.
21) What is the main product when Th undergoes beta decay?
A) Ra
B) Ac
C) Pa
D) Th
E) none of the above
22) What is the main product when U undergoes beta decay?
A) Th
B) Np
C) Pa
D) Th
E) none of the above
23) Which of the following nuclides will undergo beta decay to produce Am?
A) Bk
B) Np
C) Pu
D) Cm
E) none of the above
24) What is the missing particle?
A) positron
B) beta particle
C) alpha particle
D) gamma particle
E) none of the above
25) Which statement about gamma radiation is FALSE?
A) The symbol is: γ.
B) They have low ionization energy.
C) They have high penetrating power.
D) They are high energy photons.
E) All of the above are true.