Nuclear Group Quiz!
Name _________________________________________________
Score________
Answer each of the following questions regarding radioactivity.
(a) Write the nuclear equation for decay of 234
94 Pu by alpha emission.
(b) Account for the fact that the total mass of the products of the reaction in part (a) is slightly
less than that of the original 234
94 Pu .
(c) Describe how , , and  rays each behave when they pass through an electric field. Use the
diagram below to illustrate your answer.
(d) Why is it not possible to eliminate the hazard of nuclear waste by the process of
incineration?
Answer:
4
(a) 234
94 Pu  2  +
230
92
U
Due to a printing error, the student’s answer booklet had the Pu-239 isotope. Therefore, the following is a valid response.
239
94
Pu  24 +
235
92
U
(b) This mass defect has been converted into energy. E = mc2
(c) An alpha particle,  or He nuclei, has a 2+ charge and would be attracted to the (-) side of
the electric field. A beta particle, , or electron, has a single negative charge and is attracted
to the positive side of the electric field, but since it is much lighter and faster than an alpha it
would not be as strongly deflected. Gamma, , rays are not charged and, therefore, not
deflected by the electric field.
(d)
The half-life of a radionuclide is independent of its environment. Incineration will neither
accelerate its decay nor render it non-radioactive.
8) 1997
(a) 94-Pu-239 ---> 2-He-4 + 92-U-225
Notes; One point is earned for [He] (or ), one point for correct total mass number in
products, and one point for consistent atomic numbers and symbols. Full credit is also
earned for correct decay starting with Pu-234 (as was printed on the green insert)
(b) Missing mass is converted to energy (or "E=mc2")
Notes; No point earned for just mentioning "mass defect".
(c) In words, or drawn on diagram:
path of  particle bends toward negative (-) plate, 1 point
path of  particle bends toward positive (+) plate, 1 point
path of  ray is undeflected. 1 point
(d) Incineration (combustion, oxidation) is a chemical process AND as such it has no
effect on a nuclear process (decay). 1 point
Notes; No point for thermodynamic, kinetic, or equilibrium arguments. No point earned
for "dispersion of material is bad for the environment" or similar statements.
C 1. When 214
84𝑃𝑜 decays, the emission consists consecutively of an alpha particle, then two beta
particles, and finally another alpha particle. The resulting stable nucleus is
(A) 206
83𝐵𝑖
(B) 210
83𝐵𝑖
206
(C) 82𝑃𝑏
(D) 208
82𝑃𝑏
210
(E) 81𝑇𝑙
A 2. The radioactive decay of
(A) beta particle emission
(B) alpha particle emission
(C) positron emission
(D) electron capture
(E) neutron capture
14
6𝐶
to
14
7𝑁
occurs by the process of
131
D 3. 251
98𝐶𝑓  2 n + 54𝑋𝑒 + __
What is the missing product in the nuclear reaction represented above?
(A) 118
42𝑀𝑜
118
(B) 44𝑅𝑢
(C) 120
42𝑀𝑜
(D) 120
44𝑅𝑢
122
(E) 46𝑃𝑑
4) Which of these nuclides is most likely to be radioactive?
27
A) 60
B) 13
Al
C) 189
D) 1428 Si
E)
28 Ni
88 Ra
Answer: C
178
82
Pb
13
25) In the nuclear transmutation, 16
8 O (p, α) 7 N, what is the bombarding particle?
A) an alpha particle
B) a beta particle
C) a gamma photon
D) a proton
E) a phosphorus nucleus
Answer: D
6) The mass of a proton is 1.00728 amu and that of a neutron is 1.00867 amu. What is the
binding energy (in J) of a 60
27 Co nucleus? (The mass of a cobalt-60 nucleus is 59.9338 amu.)
A) 2.74 × 10-19
B) 9.12 × 10-28
C) 4.94 × 10-13
D) 8.20 × 10-11
E) 2.74 × 10-16
Answer: D