Deck 26: Nuclear Chemistry

Question 1

Which of the following types of radiation will pass through a piece of paper,but will be stopped by 0.5 cm of lead?

A) ( $\alpha$ )
B) ( $\beta$ )
C)
D) ( $\gamma$ )
E) All of the above will pass through 0.5 cm of lead.

Answer 1

( $\beta$ )

Question 2

What is the charge on a positron?

A) +2
B) +1
C) 0
D) -1
E) -2

Answer 2

+1

Question 3

Rank the following types of radiation from least penetrating to most penetrating: $\alpha$ , $\beta$ or $\gamma$

A) ( $\alpha$ < $\beta$ < $\gamma$ )
B) ( $\beta$ < $\gamma$ < $\alpha$ )
C) ( $\gamma$ < $\beta$ < $\alpha$ )
D) ( $\alpha$ < $\gamma$ < $\beta$ < )
E) ( $\beta$ < $\alpha$ < $\gamma$ )

Answer 3

( $\alpha$ < $\beta$ < $\gamma$ )

Question 4

Which particle has the same mass as a beta particle?

A) a neutron
B) a proton
C) a gamma ray
D) an alpha particle
E) a positron

Question 5

What nucleus decays by successive $\beta$ , $\beta$ , $\alpha$ emissions to produce uranium-236?

A)
B)
C)
D)
E)

Question 6

In one type of decay process,a neutron in the nucleus is converted to a proton and another particle which is ejected (emitted)from the nucleus.What is the identity of the ejected particle?

A) positron
B) beta particle
C) alpha particle
D) deuteron
E) neutron

Question 7

When ⁶¹Cu undergoes electron capture,what is the product nuclide?

A) (⁶⁰Ni)
B) (⁶⁰Zn)
C) (⁶⁰Cu)
D) (⁶¹Ni)
E) (⁶¹Zn)

Question 8

If a nucleus emits an alpha particle

A) its atomic number decreases by four and its mass number decreases by two.
B) its atomic number decreases by two and its mass number decreases by four.
C) its atomic number increases by two and its mass number decreases by two.
D) its atomic number is unchanged and its mass number is unchanged.
E) its atomic number is unchanged and its mass number decreases by four.

Question 9

If a nucleus gains a neutron and then undergoes beta emission,

A) its atomic number decreases by one and its mass number increases by one.
B) its atomic number is unchanged and its mass number increases by one.
C) both its atomic number and its mass number are unchanged.
D) its atomic number increases by one and its mass number is unchanged.
E) its atomic number increases by one and its mass number increases by one.

Question 10

Which of the following reactions is an example of beta decay?

A)
B)
C)
D)
E)

Question 11

Which of the following reactions is an example of beta emission?

A)
B)
C)
D)
E)

Question 12

How many alpha decays are required to convert ²³⁴U to ²²²Rn?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 13

If a nucleus undergoes positron particle emission

A) its atomic number decreases by four and its mass number decreases by two.
B) its atomic number decreases by two and its mass number decreases by four.
C) its atomic number increases by one and its mass number is unchanged.
D) its atomic number decreases by one and its mass number is unchanged.
E) its atomic number is unchanged and its mass number decreases by one.

Question 14

Which of the following symbols represents a positron?

A)
B)
C)
D)
E)

Question 15

What is the product nuclide if U undergoes five successive alpha decays?

A)
B)
C)
D)
E)

Question 16

When a nucleus undergoes radioactive decay,its new mass number is

A) always less than its original mass number.
B) never more than its original mass number.
C) never less than its original mass number.
D) always the same as its original mass number.
E) always more than its original mass number.

Question 17

If astatine-207 decays by $\alpha$ emission,followed by $\alpha$ emission,followed by electron capture,what nucleus is produced?

A)
B)
C)
D)
E)

Question 18

Which particle does the nuclide symbol $\gamma$ represent?

A) gamma ray
B) helium nucleus
C) electron
D) proton
E) positron

Question 19

When the radioactive nuclide
Undergoes alpha emission,what is the product nuclide?

A)

B)

C)

D)

E)

Question 20

If a nucleus decays by successive $\alpha$ , $\beta$ , $\beta$ particle emissions,its atomic number will

A) decrease by four.
B) decrease by two.
C) increase by four.
D) increase by two.
E) be unchanged.

Question 21

The half-life of ⁴²K is 12.5 h.How much will remain after 83 h if the original sample contained 256 g of ⁴²K?

A) 22 g
B) 2.6 g
C) 15 g
D) 20 g
E) 14 g

Question 22

The molar nuclear mass of fluorine-19 is 18.99840 g/mol.The molar mass of a proton is 1.007825 g/mol.The molar mass of a neutron is 1.008665 g/mol.Calculate the binding energy (in J/mol)of F-19.(c = 2.998 $\times$ 10⁸ m/s)

A) 6.753 $\times$ 10¹² J/mol
B) 7.131 $\times$ 10¹² J/mol
C) 1.426 $\times$ 10¹³ J/mol
D) 8.609 $\times$ 10¹⁴ J/mol
E) 8.538 $\times$ 10¹⁴ J/mol

Question 23

The point of maximum stability in the binding energy curve occurs in the vicinity of which one of the following isotopes?

A)
B)
C)
D)
E)

Question 24

When
Undergoes beta emission,what is the product nuclide?

A)
B)
C)
D)
E)

Question 25

When the radioactive nuclide
Undergoes positron emission,what is the product nuclide?

A)
B)
C)
D)
E)

Question 26

By what (single step)process does polonium-218 change to lead-214?

A) ( $\alpha$ ) particle emission
B) ( $\beta$ ) particle emission
C) positron emission
D) electron capture
E) neutron capture

Question 27

The bismuth-209 nucleus has a binding energy per nucleon of J.Determine the difference in mass between one mole of bismuth-209 nuclei and the component nucleons of which it is made.

A) 1.71 $\times$ 10^-3 kg
B) 3.92 $\times$ 10^-8 kg
C) 8.20 $\times$ 10^-6 kg
D) 2.56 $\times$ 10^-10 kg
E) 6.81 $\times$ 10^-4 kg

Question 28

Calculate the mass defect for an atom of whose isotope mass is 16.9991 g/mol.mass of proton ( )
1)00783 g/mol.mass of neutron ( )
1)00867 g/mol.

A) 0.153 g/mol
B) 0.152 g/mol
C) 0.148 g/mol
D) 0.147 g/mol
E) 0.142 g/mol

Question 29

Calculate the energy released (per mole of deuterium consumed)for the following fusion reaction, given the following molar masses of nucleons and nuclei.(c = 2.998 $\times$ 10⁸ m/s)

A) 5.63 $\times$ 10⁶ J/mol
B) 1.69 $\times$ 10¹⁵ J/mol
C) 4.62 $\times$ 10¹³ J/mol
D) 8.44 $\times$ 10¹¹ J/mol
E) 1.69 $\times$ 10¹² J/mol

Question 30

Radioactive isotopes with greater than 83 protons in the nucleus that sit below the band of stability are most likely to decay by what mode(s)?

A) alpha emission
B) beta emission
C) positron emission or alpha emission
D) electron capture or beta emission
E) electron capture or positron emission

Question 31

By what (single step)process does americium-241 decay to neptunium-237?

A) ( $\alpha$ ) particle emission
B) ( $\beta$ ) particle emission
C) positron emission
D) electron capture
E) neutron capture

Question 32

What is the nuclear binding energy per nucleon of a nucleus? (c = 3.00 $\times$ 10⁸ m/s,1 amu = 1.66054 $\times$ 10^-27 kg)

A) J/nucleon
B) J/nucleon
C) J/nucleon
D) J/nucleon
E) J/nucleon

Question 33

A certain radioactive isotope has a rate constant of decay of 2.74 $\times$ 10^-2 min^-1.Calculate the time required for a sample of this isotope to decay to one-fourth of its initial value.

A) 25.3 min
B) 31.6 min
C) 0.0548 min
D) 50.6 min
E) 2.74 min

Question 34

Which of the following nuclides has the highest nuclear binding energy per nucleon?

A)
B)
C)
D)
E)

Question 35

Write a balanced reaction for the decay of barium-127 by positron emission.

A)
B)
C)
D)
E)

Question 36

All of the following statements concerning nuclei are true EXCEPT

A) only hydrogen-1 and helium-3 have more protons than neutrons.
B) from He to Ca,stable nuclei have roughly equal numbers of protons and neutrons.
C) elements with odd atomic numbers have more stable isotopes than do those with even atomic numbers.
D) the neutron to proton ratio in stable nuclei increases as mass increases.
E) more stable isotopes have an even number of neutrons than an odd number.

Question 37

Which of the following is the most probable mode of radioactive decay for ?

A) beta emission
B) gamma emission
C) electron capture
D) alpha emission
E) positron emission

Question 38

All isotopes with atomic number greater than ____ are radioactive.

A) 43
B) 80
C) 86
D) 83
E) 90

Question 39

What nucleus decays by beta emission to produce chlorine-35?

A)
B)
C)
D)
E)

Question 40

What is the percent activity of a radioactive sample (relative to its original activity)that has undergone two half-lives of decay?

A) 25.0%
B) 12.5%
C) 6.25%
D) 3.13%
E) 75.0%

Question 41

If a tree dies and the trunk remains undisturbed for 14874 years,what percentage of original is still present? (half-life of
= 5730 years)

A) 33%
B) 25%
C) 83%
D) 17%

Question 42

What role do the cadmium control rods play in a fission reactor?

A) The rods control the rate of fission by absorbing neutrons.
B) The cadmium combines with spent uranium fuel to produce a non-radioactive product.
C) The rods focus the neutrons toward the center of the reactor.
D) The cadmium acts as a catalyst,enabling fission to occur at lower temperatures.
E) The rods move forward and backward,driving the pistons that turn the turbines.

Question 43

A sample of a radioactive isotope is found to have lost 14.0% of its original activity after 8.67 days.What is the rate constant for decay of this isotope?

A) 0.0174 d^-1
B) 0.227 d^-
C) 1.31 d^-1
D) 0.0151 d^-1
E) 0.514 d^-1

Question 44

The half-life of carbon-14 is 5730 years.If a sample initially contains 2.67 mg carbon-14,what mass remains in the sample after 2.40 $\times$ 10⁴ years?

A) 0.0 mg
B) 0.17 mg
C) 0.92 mg
D) 0.15 mg
E) 0.64 mg

Question 45

One means of enriching the percentage of uranium-235 for use as nuclear fuel is ____.

A) liquid distillation
B) gaseous centrifugation
C) mass spectroscopy
D) gamma ray bombardment
E) ion chromatography

Question 46

When ²³⁵U collides with one neutron,fission occurs.What is one possible set of products?

A) four neutrons,
,and
B) four neutrons,
,and
C) four neutrons,
,and
D) four neutrons,
,and
E) four neutrons,
,and

Question 47

The half-life for the spontaneous decay of technetium-99m is 6.0 hours.How much of a 0.20 g sample of this isotope remains after 4.5 hours?

A) 0.05 g
B) 0.08 g
C) 0.12 g
D) 0.15 g
E) 0.20 g

Question 48

A sample of phosphorus-32 is found to have an activity of 885 disintegrations per hour (dph).After 25 hours the activity has decreased to 841 dph.What is the rate constant for the decay of phosphorus-32?

A) 0.0038 hr^-1
B) 0.0020 hr^-1
C) 0.15 hr^-1
D) 490 hr^-1
E) 0.12 hr^-1

Question 49

A Geiger-M ller counter measures radiation by detecting

A) cations produced from radiation colliding with phosphor gases.
B) alpha and beta particles as they strike a detector window.
C) the increase in temperature when a gas is struck by radiation.
D) flashes of light emitted from a phosphor affected by radiation.
E) electrons released when gas atoms are ionized by the radiation.

Question 50

Uranium-235 has a half-life of 7.04 $\times$ 10⁸ years.How many years will it take for 99.9% of a U-235 sample to decay?

A) 7.0 $\times$ 10⁵ yr
B) 1.0 $\times$ 10⁶ yr
C) 4.7 $\times$ 10⁹ yr
D) 4.9 $\times$ 10⁹ yr
E) 7.0 $\times$ 10⁹ yr

Question 51

Complete the following fission reaction.

A)
B)
C)
D)
E)

Question 52

Strontium-90 is produced in nuclear fission reactors.If ingested it can replace calcium in the bones.The half-life of ⁹⁰Sr is 27.7 years.If the activity of ⁹⁰Sr in the bones of an exposed person were 90 disintegrations per second,how long would it take the activity of ⁹⁰Sr to decrease to 7.8 disintegrations per second?

A) 98 years
B) 67 years
C) 46 years
D) 56 years
E) 77 years

Question 53

Which three steps,placed in the proper order,are required for a nuclear chain reaction?

A) propagation,equilibration,and termination
B) propagation,oxidation,equilibration
C) equilibration,propagation,termination
D) initiation,oxidation,propagation
E) initiation,propagation,and termination

Question 54

Which of the following elements undergoes nuclear fusion to provide the primary source of energy from the sun?

A) helium
B) uranium
C) hydrogen
D) carbon
E) boron

Question 55

Which of the following statements is/are CORRECT?
1)The transuranium elements are created in a nuclear reaction sequence that begins with bombardment of a lighter nucleus with low energy helium nuclei.
2)A low energy neutron may be captured by a nucleus,giving a product in which the mass number is increased by one unit.
3)Nuclear reactions involving neutron capture followed by gamma ray emission are referred to as (n, $\gamma$ )reactions.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 56

Which two nuclei are the two fissionable isotopes most commonly used in nuclear reactors?

A) and
B) and
C) and
D) and
E) and

Question 57

A 4.50-mg sample of a newly discovered radioactive nuclide was analyzed and found to contain only 3.25 mg after a period of 30.3 h.What is the half-life of the nuclide?

A) 76.3 h
B) 64.5 h
C) 73.8 h
D) 11.1 h
E) 17.6 h

Question 58

A radioactive isotope undergoes decay by emission of a positron.After 2.00 h,6.720% of the initial amount of the isotope remains undecayed.What is the half-life of this isotope?

A) 45.0 min
B) 30.8 min
C) 90.0 min
D) 15.0 min
E) 60.0 min

Question 59

Which of the following statements is/are CORRECT?
1)Naturally occurring isotopes account for only a small fraction of known radioactive isotopes.
2)A few radioactive isotopes with long half-lives,such as U-235 and U-238,are found in nature.
3)Trace quantities of some short-lived radioactive isotopes,such as C-14,are found in nature because they are formed continuously by nuclear reactions.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 60

The rate constant for the decay of a radioactive isotope is 4.231 $\times$ 10^-3 / day.What is the half-life of this isotope?

A) 327.6 days
B) 409.5 days
C) 81.90 days
D) 163.8 days
E) none of these

Question 61

Complete the following fusion reaction. +
$\to$ ____ +

A)
B)
C)
D)
E)

Question 62

What particle(s)are produced in the following reaction?

A)
B)
C)
D)
E)

Question 63

Explain the treatment named boron neutron capture therapy (BNCT).

Question 64

Explain the difference between 1 rad and 1 rem of radiation.

Question 65

At the high temperatures necessary for fusion,matter exists as a plasma,which is

A) a liquid form of a radioactive element.
B) a gaseous cloud of electrons and positrons.
C) a mixture of unbound nuclei and electrons.
D) an equal mixture of matter and anti-matter.
E) a dense solid composed of neutrons.

Question 66

In boron neutron capture therapy (BNCT),boron-10 is injected into a tumor.When the tumor is irradiated with neutrons,boron nuclei capture the neutrons and disintegrate into two particles.These particles are lithium-7 and a(n)____.

A) alpha particle
B) beta particle
C) positron
D) deuterium nuclei
E) helium nuclei

Question 67

In positron emission tomography (PET),a positron emitted from an unstable isotope travels a short distance before it is annihilated by

A) an electron,creating a proton that is detected by the instrument.
B) a neutron,creating two gamma rays that travel in opposite directions.
C) an electron,creating two gamma rays that travel in opposite directions.
D) an alpha particle,creating two protons that travel in opposite directions.
E) gamma ray,creating an electron that is detected by the instrument.

Question 68

A 0.20-mL sample of a solution containing that produces 3.7 $\times$ 10³ cps is injected into the bloodstream of an animal.After allowing circulatory equilibrium to be established,a 0.20-mL sample of blood is found to have an activity of 31 cps.Calculate the blood volume of the animal.

A) 24 mL
B) 0.60 L
C) 12 mL
D) 119 mL
E) none of these

Question 69

Which of the following types of radiation has the greatest quality factor?

A) beta particles
B) alpha particles emitted within the body
C) gamma rays
D) low energy protons
E) low energy neutrons

Question 70

Which of the following statements concerning neutron activation analysis is/are CORRECT?
1)In neutron activation analysis,a neutron is ejected from an atom creating a new isotope that is one mass unit lower.
2)Neutron activation analysis is destructive,but requires less than 1 g of sample.
3)Neutron activation analysis creates isotopes in the excited state that emit gamma rays to return to the ground state.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 71

Which of the following isotopes is used in the treatment of thyroid disorders?

A)
B)
C)
D)
E)

Question 72

All isotopes of atomic number greater than ________ are unstable and radioactive.

Question 73

Which of the following statements concerning radiation absorption by living tissue is/are CORRECT?
1)The "quality factor" takes into account the differences in damaging power of the various forms of radiation.
2)One gray denotes the absorption of 1 joule per kilogram of tissue.
3)The SI unit for biological damage is a sievert (Sv),which is determined by multiplying grays by the quality factor.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 74

A unit used to quantify biological damage is called the ________ or rem.

Question 75

Neutron ________ analysis is a non-destructive process in which a sample is irradiated with neutrons.The neutrons react with nuclei to form isotopes with masses one unit higher than the original nuclei.The nuclei are formed in excited states and they emit gamma radiation that can be used to both identify the presence of an element and quantify how much is present.

Question 76

The becquerel is an SI unit for the measurement of radiation.One Bq represents

A) 1 J energy absorbed per kg of tissue.
B) 3.7 $\times$ 10¹⁰ disintegrations per second.
C) 1 disintegration per second.
D) 0.01 J energy absorbed per kg of tissue.
E) 1 calorie energy absorbed per kg of tissue.

Question 77

Technetium-99m is routinely used in medical imaging.The italics m means the nucleus is ________.

Question 78

Complete the following fusion reaction.

A)
B)
C)
D)
E)

Question 79

What percentage of the world's electricity is supplied by nuclear fusion reactors?

A) 0%
B) 3%
C) 8%
D) 17%
E) 39%