Chapter 24 Practice Worksheet
Name: ___________________________________________
14
1) Consider the two nuclides 56
26𝐹𝑒 and 6𝐶 .
a. Determine the number of protons in each nucleus.
b. Determine the number of neutrons in each nucleus.
2) Identify the missing term in each of the following nuclear equations. Write the element’s symbol, its atomic number, and its
mass number.
1
4
a. 146𝐶 → −10𝑒 + ________
b. 63
29𝐶𝑢 + 1𝐻 → 2𝐻𝑒 + ________
3) What element is formed when each of the following radioisotopes undergoes alpha decay? Give the atomic number and
mass number of the element.
a.
polonium-212 ( 212
84𝑃𝑜 )
b.
uranium-238 ( 238
92𝑈 )
c.
astatine-218 ( 218
85𝐴𝑡 )
d.
polonium-214 ( 214
84𝑃𝑜 )
4) What element is formed when each of the following radioisotopes undergoes beta decay? Give the atomic number and mass
number of the element.
a.
b.
c.
d.
3
1𝐻
235
92𝑈
60
26𝐹𝑒
234
90𝑇ℎ
5) Calculate the neutron-to-proton ratio for each of the following isotopes.
a. 126𝐶
c. 222
86𝑅𝑛
b.
32
16𝑆
d.
234
90𝑇ℎ
6) Write a balanced nuclear equation for the alpha decay of each of the following radioisotopes.
b. radon-222 ( 222
a. polonium-210 ( 210
c. uranium-234 ( 234
d. thorium-230 ( 234
86𝑅𝑛 )
84𝑃𝑜 )
92𝑈 )
90𝑇ℎ )
7) Write a balanced nuclear equation for the beta decay of each of the following radioisotopes.
a. 62𝐻𝑒
c. 62
d.
b. 235
27𝐶𝑜
92𝑈
234
90𝑇ℎ
8) Complete each of the following nuclear equations.
a.
38
19𝐾
→
0
−1𝑒
+ ________
b.
142
61𝑃𝑚
+
0
−1𝑒
→ ________
9) Complete the nuclear equation for each of the following induced transmutation reactions.
a.
253
99𝐸𝑠
+ 42𝐻𝑒 → 10𝑛 + ________
b. 49𝐵𝑒 + 42𝐻𝑒 → 10𝑛 + ________
10) Use the Half-Lives of Several Radioisotopes Table to answer the following questions.
a. How much of a 2.000x103 mg sample of polonium-214 will remain after
Half-Lives of Several Radioisotopes
1637 microseconds?
Radioisotope
Symbol
Half-Life
b. How much of a 50.0-g sample of tritium (H-3) will remain after
37 years?
c. How much of a 20.0-g sample of carbon-14 will remain after one halflife? After 17,190 years?
11) Phosphorus-32 has a half-life of 14.3 days. How many days will it take
for a sample of phosphorus-32 to decay to one-eighth its original amount?
Polonium-214
Cobalt-60
Radon-222
Phosphorus-32
Carbon-14
Uranium-238
Hydrogen-3
214
84𝑃𝑜
60
27𝐶𝑜
222
86𝑅𝑎
32
15𝑃
14
6𝐶
238
92𝑈
3
1𝐻
163.7 μs
5.272 y
3.8 d
14.28 d
5730 y
4.46 x 109 y
12.3 y
12) Iodine-131 has a half-life of 8.0 days. How many grams of an original 160 mg sample will remain after 40 days?
13) Carbon-14 has a half-life of 5715 years. It is used to determine the age of ancient objects. If a sample today contains 0.060
mg of carbon-14, how much carbon-14 must have been present in the sample 11,430 years ago?
14) Match the item on the left with its description on the right.
_____ Geiger-Müller counter
_____ scintillation counter
_____ film badge
_____ radioactive tracers
(a) device that uses film to measure the approximate
radiation exposure of people working with radiation
(b) instrument that converts scintillating light to an
electric signal for detecting radiation
(c) meter that detects radiation by counting electric
pulses carried by gas ionized by radiation
(d) radioactive atoms that are incorporated into
substances so that movement of the substances can be
followed by detectors
15) Which type of radiation is easiest to shield? Why?
16) One technique for dating ancient rocks involves uranium-235, which has a half-life of 710 million years. Rocks originally
rich in uranium-235 will contain small amounts of its decay series, including the nonradioactive lead-206. Explain the
relationship between a sample’s relative age and the ratio of lead-206 to uranium-235 in the sample.
17) The technetium-99 isotope has a half-life of 6.0 h. If a 100. mg sample of technetium-99 were injected into a patient, how
many milligrams would still be present after 24 h?
18)A Geiger-Müller counter, used to detect radioactivity, registers 14 units when exposed to a radioactive isotope. What would
the counter read, in units, if that same isotope is detected 60 days later? The half-life of the isotope is 30 days.
19) The Sun is powered by the fusion of hydrogen atoms into helium atoms. When the Sun has exhausted its hydrogen supply,
it could fuse helium-4, forming carbon-12. Write a balanced nuclear equation for this process.
275
20) Write a fusion reaction that could theoretically produce one atom of 113 Uut .
21.Match each of the following statements with the process(es) to which they apply, using one of the choices below:
(1) fission only
(3) both fission and fusion
(2) fusion only
(4) neither fission nor fusion
_____
a.A very large nucleus splits into smaller pieces.
_____
b.The total mass before a reaction is greater than the mass after a reaction.
_____
c.The rate of a reaction can be safely controlled for energy generation in suitable vessels.
_____
d.Two small nuclei form a single larger one.
_____
e.Less-stable nuclei are converted to more-stable nuclei.
22.Match the reaction type on the right to the statement(s) that applies to it on the left.
_____ It requires very high temperatures.
(a) uncontrolled fusion
_____ It is used in nuclear reactors to make electricity.
(b) uncontrolled fission
_____ It occurs in the sun and other stars.
(c) controlled fusion
_____ It is used in atomic bombs.
(d) controlled fission
23.Match the component of a nuclear power plant on the right to its use on the left.
_____ limits the number of free neutrons
(a) moderator
_____ is used to slow down neutrons
(b) fuel rod
_____ drives an electric generator
(c) control rod
_____ provides neutrons by its fission
(d) shielding
_____ removes heat from the system safely
(e) coolant
_____ prevents escape of radiation
(f) turbine
24.
(a)
(b)
(c)
(d)
_____ A chain reaction is any reaction in which
excess reactant is present.
the material that starts the reaction is also a product.
the rate is slow.
many steps are involved.
25.As a star ages, does the ratio of He atoms to H atoms in its composition become larger, smaller, or remain constant? Explain
your answer.
Chapter 24 Summary
26. What is radioactivity?
27. How do neutrons affect the stability of an atom’s nucleus?
28. Relate nuclear stability to an atom’s size and its neutron-to-proton ratio.
29. Look at The Band of Stability Figure in your textbook. Determine where on the graph each of the following isotopes would
fall: above, within, or below the band of stability.
a. 146 C
b. 107
47 Ag
c. an isotope with an atomic number near 50 and an
n/p ratio of 1.1:1
d. an isotope with an atomic number near 45 and an
n/p ratio of 1.5:1
29. Which radioactive decay processes increase the neutron-to-proton ratio of a nucleus? Which process decreases the
neutron-to-proton ratio?
30. Can carbon dating be used to date accurately the remains of an animal thought to be 1 million years old? Explain your
answer.
31. What is induced transmutation? How does it relate to the transuranium elements?
32. List three devices that are used to detect and measure radiation.
33. What is the difference between nuclear fusion and nuclear fission?
34. What effect does radiation have on living cells? What dose is considered safe?