Chapter 17, Radioactivity and Nuclear Chemistry Video Solutions, Introductory Chemistry

Chapter Questions

02:06

Problem 1

What is radioactivity? What does it mean for an atom to be radioactive?

Sharfa F.

Numerade Educator

01:42

Problem 2

How was radioactivity first discovered? By whom?

Sharfa F.

Numerade Educator

01:08

Problem 3

What are uranic rays?

Sharfa F.

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02:29

Problem 4

What role did Marie Sklodowska Curie play in the discovery of radioactivity? How was she acknowledged for her work in radioactivity?

Sharfa F.

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01:42

Problem 5

Explain what each symbol in the notation represents. $$\frac{A}{Z} X$$

Sharfa F.

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00:47

Problem 6

Radioactivity originates from the ______ of radioactive
atoms.

Sharfa F.

Numerade Educator

01:40

Problem 7

What is alpha radiation? What is the symbol for an alpha particle?

Sharfa F.

Numerade Educator

01:21

Problem 8

What happens to an atom when it emits an alpha particle?

Sharfa F.

Numerade Educator

00:58

Problem 9

How do the ionizing power and penetrating power of alpha particles compare to other types of radiation?

Sharfa F.

Numerade Educator

01:41

Problem 10

What is beta radiation? What is the symbol for a beta particle?

Sharfa F.

Numerade Educator

01:07

Problem 11

What happens to an atom when it emits a beta particle?

Sharfa F.

Numerade Educator

01:01

Problem 12

How do the ionizing power and penetrating power of beta particles compare to other types of radiation?

Sharfa F.

Numerade Educator

01:29

Problem 13

What is gamma radiation? What is the symbol for a gamma ray?

Sharfa F.

Numerade Educator

01:03

Problem 14

What happens to an atom when it emits a gamma ray?

Sharfa F.

Numerade Educator

01:02

Problem 15

How do the ionizing power and penetrating power of gamma particles compare to other types of radiation?

Sharfa F.

Numerade Educator

01:24

Problem 16

What is positron emission? What is the symbol for a positron?

Sharfa F.

Numerade Educator

01:07

Problem 17

What happens to an atom when it emits a positron?

Sharfa F.

Numerade Educator

01:09

Problem 18

How do the ionizing power and penetrating power of positrons compare to other types of radiation?

Sharfa F.

Numerade Educator

03:30

Problem 19

What is a nuclear equation? What does it mean for a nuclear equation to be balanced?

Sharfa F.

Numerade Educator

01:51

Identify the parent nuclides and daughter nuclides in the nuclear equation. Which kind of radioactive decay is involved? $$_{91}^{231} \mathrm{Pa} \longrightarrow_{89}^{227} \mathrm{Ac}+_{2}^{4} \mathrm{He}$$

Sharfa F.

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02:24

Problem 21

What is a film-badge dosimeter, and how does it work?

Sharfa F.

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03:24

Problem 22

How does a Geiger-Müller counter detect radioactivity?

Sharfa F.

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02:55

Problem 23

Explain how a scintillation counter works.

Sharfa F.

Numerade Educator

01:30

Problem 24

What are some sources of natural radioactivity?

Sharfa F.

Numerade Educator

02:14

Problem 25

Explain the concept of half-life.

Sharfa F.

Numerade Educator

01:28

Problem 26

What is a radioactive decay series?

Sharfa F.

Numerade Educator

03:03

Problem 27

What is the source of radon in our environment? Why is radon problematic?

Sharfa F.

Numerade Educator

02:31

Problem 28

What is the source of carbon-14 in our environment? Why do all living organisms contain a uniform amount of carbon-14?

Sharfa F.

Numerade Educator

05:06

Problem 29

What happens to the carbon-14 in a living organism when it dies? How can this be used to establish how long ago the organism died?

Sharfa F.

Numerade Educator

02:51

Problem 30

How do we know that carbon-14 (or radiocarbon) dating is accurate? What is the age limit for which carbon-14 dating is useful?

Sharfa F.

Numerade Educator

02:41

Problem 31

Explain Fermi's experiment in which he bombarded uranium with neutrons. Include a nuclear equation in your answer.

Sharfa F.

Numerade Educator

01:52

Problem 32

What is nuclear fission? How and by whom was it discovered?

Sharfa F.

Numerade Educator

02:40

Problem 33

Why can nuclear fission be used in a bomb? Include the concept of a chain reaction in your explanation.

Sharfa F.

Numerade Educator

01:56

Problem 34

What is a critical mass?

Sharfa F.

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02:24

Problem 35

What was the main goal of the Manhattan Project? Who was the project leader?

Sharfa F.

Numerade Educator

01:39

Problem 36

How can nuclear fission be used to generate electricity?

Sharfa F.

Numerade Educator

01:39

Problem 37

Explain the purpose of the control rods in a nuclear reactor core. How do they work?

Sharfa F.

Numerade Educator

04:55

Problem 38

What are the main advantages and problems associated with nuclear electricity generation?

Sharfa F.

Numerade Educator

02:50

Problem 39

Can a nuclear reactor detonate the way a nuclear bomb can? Why or why not?

Sharfa F.

Numerade Educator

00:41

Problem 40

What is nuclear fusion?

Ren Jie T.

Numerade Educator

03:14

Problem 41

Do modern nuclear weapons use fission, fusion, or both? Explain.

Sharfa F.

Numerade Educator

04:39

Problem 42

Can nuclear fusion be used to generate electricity? What are the advantages of fusion over fission for electricity generation? What are the problems with fusion?

Sharfa F.

Numerade Educator

01:47

Problem 43

How does radiation affect the molecules within living organisms?

Sharfa F.

Numerade Educator

02:55

Problem 44

What is acute radiation damage to living organisms?

Sharfa F.

Numerade Educator

01:57

Problem 45

Explain how radiation can increase cancer risk.

Sharfa F.

Numerade Educator

05:53

Problem 46

Explain how radiation can cause genetic defects. Has this ever been observed in laboratory animals? In humans?

Sharfa F.

Numerade Educator

01:07

Problem 47

What is the main unit of radiation exposure? How much radiation is the average U.S. resident exposed to per year?

Sharfa F.

Numerade Educator

03:00

Problem 48

Describe the outcomes of radiation exposure at different doses (in rem).

Sharfa F.

Numerade Educator

01:33

Problem 49

Explain the medical use of isotope scanning.

Sharfa F.

Numerade Educator

01:01

Problem 50

How is radioactivity used to treat cancer?

Sharfa F.

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01:38

Problem 51

Draw the symbol for the isotope of lead that contains 128 neutrons.

Sharfa F.

Numerade Educator

01:26

Problem 52

Draw the symbol for the isotope of bismuth that contains
124 neutrons.

Sharfa F.

Numerade Educator

01:24

Problem 53

How many protons and neutrons are in this nuclide?
$$
\begin{array}{c}
207 \mathrm{Tl} \\
81
\end{array}
$$

Sharfa F.

Numerade Educator

01:20

Problem 54

How many protons and neutrons are in this nuclide? $$
{ }_{86}^{219} \mathrm{Rn}
$$

Sharfa F.

Numerade Educator

01:22

Problem 55

Identify the particle represented by each symbol as an alpha particle, a beta particle, a gamma ray, a positron, a neutron, or a proton.
(a) $-1 \mathrm{e}$
(b) ${ }_{0}^{1} \mathrm{n}$
(c) ${ }_{0}^{0} \gamma$

Sharfa F.

Numerade Educator

01:27

Problem 56

Identify the particle represented by each symbol as an alpha particle, a beta particle, a gamma ray, a positron, a neutron, or a proton.
(a) $_{1}^{1} p$
(b) $_{2}^{4} \mathrm{He}$
(c) $+1^{0} e$

Sharfa F.

Numerade Educator

04:19

Problem 57

Complete the table. \begin{array}{ccccc}
\hline \begin{array}{c}
\text { Chemical } \\
\text { Symbol }
\end{array} & \begin{array}{c}
\text { Atomic } \\
\text { Number (Z) }
\end{array} & \begin{array}{c}
\text { Mass } \\
\text { Number (A) }
\end{array} & \begin{array}{c}
\# \\
\text { Protons }
\end{array} & \begin{array}{c}
\# \\
\text { Neutrons }
\end{array} \\
\hline \mathrm{Tc} & & 95 & & \\
& 56 & 128 & & \\
\hline \mathrm{Eu} & & & & 82 \\
\mathrm{Fr} & & & & 136 \\
\hline
\end{array}

Sharfa F.

Numerade Educator

03:45

Problem 58

Complete the table. \begin{array}{ccccc}
\hline \begin{array}{c}
\text { Chemical } \\
\text { Symbol }
\end{array} & \begin{array}{c}
\text { Atomic } \\
\text { Number (Z) }
\end{array} & \begin{array}{c}
\text { Mass } \\
\text { Number (A) }
\end{array} & \begin{array}{c}
\# \\
\text { Protons }
\end{array} & \begin{array}{c}
\text { # } \\
\text { Neutrons }
\end{array} \\
\hline \mathrm{Pd} & 46 & & & 54 \\
\mathrm{Ce} & & 136 & & \\
& 84 & 208 & & \\
\hline & & & 88 & 138 \\
\hline
\end{array}

Sharfa F.

Numerade Educator

04:32

Problem 59

Write a nuclear equation for the alpha decay of each nuclide.
(a) U-234
(b) Th-230
(c) Ra-226
(d) Rn-222

Sharfa F.

Numerade Educator

04:51

Problem 60

Write a nuclear equation for the alpha decay of each nuclide.
(a) $\mathrm{Po}-218$
(b) $\mathrm{Po}-214$
(c) $\mathrm{Po}-210$
(d) Th-227

Sharfa F.

Numerade Educator

02:49

Problem 61

Write a nuclear equation for the beta decay of each nuclide.
(a) Pb-214
(b) Bi-214
(c) Th-231
(d) Th-227

Sharfa F.

Numerade Educator

03:55

Problem 62

Write a nuclear equation for the beta decay of each nuclide.
(a) $\quad \mathrm{Pb}-211$
(b) TI-207
(c) Th-234
(d) $\mathrm{Pa}-234$

Sharfa F.

Numerade Educator

02:10

Problem 63

Write a nuclear equation for positron emission by each nuclide. (a) $\mathrm{C}-11$
(b) $\mathrm{N}-13$
(c) $0-15$

Sharfa F.

Numerade Educator

02:10

Problem 64

Write a nuclear equation for positron emission by each nuclide. (a) $\operatorname{co}-55$
(b) Na-22
(c) $\mathrm{F}-18$

Sharfa F.

Numerade Educator

04:01

Problem 65

Fill in the blanks in the partial decay series.
$$
{ }_{94}^{244} \mathrm{Pu} \longrightarrow{ }_{95}^{241} \mathrm{Am}+
$$
${ }_{95}^{241} \mathrm{Am} \longrightarrow{ }_{93}^{237} \mathrm{~Np}+$
${ }_{93}^{237} \mathrm{~Np} \longrightarrow \underline{+}{ }_{2}^{4} \mathrm{He}$
$$
\longrightarrow{ }_{92}^{233} \mathrm{U}+{ }_{-1}^{0} \mathrm{e}
$$

Sharfa F.

Numerade Educator

03:48

Problem 66

Fill in the blanks in the partial decay series.
${ }_{94}^{241} \mathrm{Pu} \longrightarrow{ }_{95}^{241} \mathrm{Am}+$______________
${ }_{95}^{241} \mathrm{Am} \longrightarrow{ }_{93}^{237} \mathrm{Np}+$____________
${ }_{93}^{237} \mathrm{Np} \longrightarrow$__________ $+{ }_{2}^{4} \mathrm{He}$
____________$\rightarrow{ }_{92}^{233} \mathrm{U}+{ }_{-1}^{0} \mathrm{e}$

Sharfa F.

Numerade Educator

02:14

Problem 67

Write a partial decay series for Th-232 undergoing these sequential decays. $$\alpha, \beta, \beta, \alpha$$

Grigoriy S.

Numerade Educator

04:26

Problem 68

Write a partial decay series for $\mathrm{Rn}-220$ undergoing these sequential decays. $$\alpha, \alpha, \beta, \alpha$$

Ryan J.

Numerade Educator

04:07

Problem 69

Suppose you a have a 100,000 -atom sample of a radioactive nuclide that decays with a half-life of 2.0 days. How many radioactive atoms are left after 10 days?

Sharfa F.

Numerade Educator

04:47

Problem 70

Iodine-131 is often used in nuclear medicine to obtain images of the thyroid. If you start with $4.0 \times 10^{10} \mathrm{I}-131$ atoms, how many are left after approximately 1 month? I-131 has a half-life of 8.0 days.

Sharfa F.

Numerade Educator

04:54

Problem 71

A patient is given $0.050 \mathrm{mg}$ of technetium- $99 \mathrm{m}$ (where $\mathrm{m}$ means metastable-an unstable but long-lived state), a radioactive isotope with a half-life of about 6.0 hours. How long until the radioactive isotope decays to $6.3 \times 10^{-3} \mathrm{mg} ?$

Sharfa F.

Numerade Educator

03:54

Problem 72

Radium-223 decays with a half-life of 11.4 days. How long does it take for a 0.240 -mol sample of radium to decay to $1.50 \times 10^{-2} \mathrm{mol} ?$

Sharfa F.

Numerade Educator

02:39

Problem 73

One of the nuclides in spent nuclear fuel is $\mathrm{U}-234,$ an alpha emitter with a half-life of $2.44 \times 10^{5}$ years. If a spent fuel assembly contains $2.80 \mathrm{kg}$ of $\mathrm{U}-234,$ how long does it take for the amount of $\mathrm{U}-234$ to decay to less than $0.10 \mathrm{kg}$ ?

Arun B.

Numerade Educator

01:58

Problem 74

One of the nuclides in spent nuclear fuel is $\mathrm{U}-235,$ an alpha emitter with a half-life of 703 million years. How long does it take for the amount of $\mathrm{U}-235$ to reach one-eighth of its initial amount?

Arun B.

Numerade Educator

01:38

Problem 75

A radioactive sample contains $2.45 \mathrm{g}$ of an isotope with a half-life of 3.8 days. How much of the isotope in grams remains after 11.4 days?

Arun B.

Numerade Educator

07:24

Problem 76

A 68 -mg sample of a radioactive nuclide is administered to
-a patient to obtain an image of her thyroid. If the nuclide Thas a half-life of 12 hours, how much of the nuclide remains in the patient after 4.0 days?

Arun B.

Numerade Educator

02:16

Problem 77

Each of the tabulated nuclides is used in nuclear medicine. List them in order of most active (largest number of decay events per second) to least active (smallest number of decay events per second). $$\begin{array}{ll}
\hline \text { Nuclide } & \text { Half-Life } \\
\hline \text { P-32 } & 14.3 \text { days } \\
\text { Cr-51 } & 27.7 \text { days } \\
\text { Ga-67 } & 78.3 \text { hours } \\
\text { Sr-89 } & 50.0 \text { days } \\
\hline
\end{array}$$

Sharfa F.

Numerade Educator

02:54

Problem 78

Each of the tabulated nuclides is used in nuclear medicine. List them in order of most active (largest number of decay events per second) to least active (smallest number of decay events per second). \begin{array}{ll}
\hline \text { Nuclide } & \text { Half-Life } \\
\hline \mathrm{Y}-90 & 64.1 \text { hours } \\
\mathrm{T}_{\mathrm{C}}-99 \mathrm{m} & 6.02 \text { hours } \\
\mathrm{In}-111 & 2.8 \text { days } \\
\mathrm{I}-131 & 8.0 \text { days } \\
\hline
\end{array}

Sharfa F.

Numerade Educator

02:40

Problem 79

A wooden boat discovered just south of the Great Pyramid in Egypt had a carbon-14 content of approximately $50 \%$ of that found in living organisms. How old is the boat?

Sharfa F.

Numerade Educator

02:12

Problem 80

A layer of peat buried beneath the glacial sediments from the last ice age had a carbon- 14 content of $25 \%$ of that found in living organisms. How long ago was this ice age?

Sharfa F.

Numerade Educator

02:45

Problem 81

An ancient skull has a carbon- 14 content of $1.563 \%$ of that found in living organisms. How old is the skull?

Sharfa F.

Numerade Educator

02:03

Problem 82

A mammoth skeleton has a carbon-14 content of $12.50 \%$ of that found in living organisms. When did the mammoth live?

Sharfa F.

Numerade Educator

00:50

Problem 83

Write the nuclear reaction for the neutron-induced fission of $\mathrm{U}-235$ to form $\mathrm{Xe}-144$ and $\mathrm{Sr}-90 .$ How many neutrons are produced in the reaction?

Tiffany N.

Numerade Educator

03:31

Problem 84

Write the nuclear reaction for the neutron-induced fission of $\mathrm{U}-235$ to produce $\mathrm{Te}-137$ and $\mathrm{Zr}-97 .$ How many neutrons are produced in the reaction?

Monica Mame Soma N.

Michigan Technological University

01:13

Problem 85

Write the nuclear equation for the fusion of two H-2 atoms to form He-3 and one neutron.

Matthew H.

Numerade Educator

01:14

Problem 86

Write the nuclear equation for the fusion of $\mathrm{H}-3$ with $\mathrm{H}-1$ to form He-4.

Monica Mame Soma N.

Michigan Technological University

04:24

Problem 87

Complete each nuclear equation.
(a) $\frac{1}{1} p+ ____{4}^{9} B e \longrightarrow+\frac{4}{2} H e$
(b) ____ $_{83}^{209} \mathrm{Bi}+\longrightarrow \longrightarrow_{11}^{272} \mathrm{Rg}+_{0} \mathrm{n}$
(c) $179 \mathrm{W}+ _{-1} \mathrm{e} \longrightarrow$

Sharfa F.

Numerade Educator

04:00

Problem 88

Complete each nuclear equation.
(a) $_{13}^{27} \mathrm{Al}+_{2}^{4} \mathrm{He} \longrightarrow+_{0}^{1} \mathrm{n}$
(b) $\quad+_{0}^{1} n \longrightarrow_{14}^{29} S i+\frac{4}{2} H e$
(c) $^{245} \mathrm{Am} \longrightarrow \frac{237}{93} \mathrm{Np}+$

Sharfa F.

Numerade Educator

02:51

Problem 89

A breeder nuclear reactor is a reactor in which U-238 (which does not undergo fission) is converted into Pu-239 (which does undergo fission). The process involves bombardment of $\mathrm{U}-238$ by neutrons to form $\mathrm{U}-239,$ which undergoes two sequential beta decays. Write nuclear equations to represent this process.

Sharfa F.

Numerade Educator

02:17

Problem 90

Write a series of nuclear equations in which Al-27 reacts with a neutron and the product undergoes an alpha decay followed by a beta decay.

Sharfa F.

Numerade Educator

06:05

Problem 91

The fission of $\mathrm{U}-235$ produces $3.2 \times 10^{-11} \mathrm{J} /$ atom. How much energy does it produce per mole of U-235? Per kilogram of U-235?

Sharfa F.

Numerade Educator

03:26

Problem 92

The fusion of deuterium and tritium produces $2.8 \times 10^{-12} \mathrm{J}$ for every atom of deuterium and atom of tritium. How much energy is produced per mole of deuterium and mole of tritium?

Sharfa F.

Numerade Educator

04:20

Problem 93

Bi-210 is a beta emitter with a half-life of 5.0 days. If a sample contains $1.2 \mathrm{g}$ of $\mathrm{Bi}-210,$ how many beta emissions occur in 5.0 days?

Sharfa F.

Numerade Educator

07:18

Problem 94

Po-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains $55 \mathrm{mg}$ of $\mathrm{Po}-218,$ how many alpha emissions occur in 6.0 minutes?

Sharfa F.

Numerade Educator

02:21

Problem 95

If a person living in a high-radon area is exposed to 0.400 rem of radiation from radon per year, and his total exposure is 0.585 rem, what percentage of his total exposure is due to radon?

Sharfa F.

Numerade Educator

02:23

Problem 96

An X-ray technician is exposed to 0.020 rem of radiation at work. If her total exposure is the national average (0.36 rem), what fraction of her exposure is due to on-the-job exposure?

Sharfa F.

Numerade Educator

03:07

Problem 97

Radium-226 (atomic mass 226.03 amu) decays to radon-224, a radioactive gas. The half-life of radium- 226 is $1.6 \times 10^{3}$ years. If a $1.5-\mathrm{g}$ sample of radium- 226 decays for 45 days, what volume of radon gas (at $25.0^{\circ} \mathrm{C}$ and $1.0 \mathrm{atm}$ ) is produced?

Arun B.

Numerade Educator

05:01

Problem 98

Consider the fission reaction. $$_{92}^{235} \mathrm{U}+_{0}^{1} \mathrm{n} \longrightarrow_{56}^{142} \mathrm{Ba}+_{36}^{91} \mathrm{Kr}+3_{0}^{1} \mathrm{n}+\text { Energy }$$ What mass of $\mathrm{Kr}-91$ (atomic mass 92.93 amu) is produced by the complete fission of $15 \mathrm{g}$ of $\mathrm{U}-235$ (atomic mass 235.04 amu)?

Sharfa F.

Numerade Educator

03:08

Problem 99

Closely examine the diagram representing the alpha decay of sodium- 20 and draw the missing nucleus.

Sharfa F.

Numerade Educator

00:32

Problem 100

Closely examine the diagram representing the beta decay of fluorine-21 and draw the missing nucleus.

Tiffany N.

Numerade Educator

02:35

Problem 101

Closely examine the diagram representing the positron emission of carbon-10 and draw the missing nucleus.

Sharfa F.

Numerade Educator

04:16

Problem 102

A radiometric dating technique uses the decay of $\mathrm{U}-238$ to Pb-206 (the half-life for this process is 4.5 billion years) to determine the age of the oldest rocks on Earth and by implication the age of Earth itself. The oldest uraniumcontaining rocks on Earth contain approximately equal numbers of uranium atoms and lead atoms. Assuming the rocks were pure uranium when they were formed, how old are the rocks?

Sharfa F.

Numerade Educator

02:13

Problem 103

Silver is electroplated at the cathode of an electrolysis cell by this half-reaction.
$$\mathrm{Ag}^{+}(a q)+\mathrm{e}^{-} \longrightarrow \mathrm{Ag}(s)$$
How many moles of electrons are required to electroplate $5.8 \mathrm{~g}$ of $\mathrm{Ag} ?$

Sharfa F.

Numerade Educator

09:35

Problem 104

Radon-220 undergoes alpha decay with a half-life of 55.6 s. If there are 16,000 atoms present initially, make a table showing how many atoms are present at 0 s, 55.6 s, $111.2 \mathrm{s}, 166.8 \mathrm{s}, 222.4 \mathrm{s},$ and $278.0 \mathrm{s} .$ (Note that the times
selected for observation are multiples of the half-life.) Make a graph of number of atoms present on the $y$ -axis and total time on the $x$ -axis.

Sharfa F.

Numerade Educator

01:23

Problem 105

Write all the balanced nuclear equations for each step of the nuclear decay sequence that starts with U-238 and ends with U-234. Refer to Figure 17.9 for the decay processes involved.

Matthew H.

Numerade Educator

01:12

Problem 106

For each member in your group, suggest one thing that all types of nuclear reactions have in common and one way in which they are different from each other. Try to get one contribution from each group member. Record your answers as complete sentences.

David C.

Numerade Educator