Deck 26: Nuclear Chemistry

Question 1

What nucleus decays by successive β,β,α emissions to produce uranium-236?

A)
B)
C)
D)
E)

Answer 1

Question 2

Which of the following particles 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

Answer 2

A positron

Question 3

When the radioactive nucleus undergoes an alpha emission,what is the product nucleus?

A)
B)
C)
D)
E)

Answer 3

Question 4

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

A)
B)
C)
D)
E)

Question 5

How many alpha decays are required to convert ²³⁴U to ²¹⁴Pb?

A) 5
B) 6
C) 3
D) 7
E) 2

Question 6

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

A)
B)
C)
D)
E)

Question 7

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) α
B) β
C) β and γ both
D) γ
E) All of the above will pass through 0.5 cm of lead.

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 undergoes alpha particle emission:

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

Question 10

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 11

If a nucleus decays by one α followed by two β particle emissions,its atomic number will _____.

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

Question 12

Which particle does the nuclide symbol b represent?

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

Question 13

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 14

When ²²⁵Th undergoes an electron capture,what is the product nucleus?

A) (²²⁴Th)
B) (²²⁶Ac)
C) (²²⁶Th)
D) (²²⁵Ac)
E) (²²⁵Pa)

Question 15

Which of the following symbols represents a positron?

A)
B)
C)
D)
E)

Question 16

What is the product nucleus if ²³⁴ U undergoes three successive alpha decays?

A) (²²²Rn)
B) (²¹⁴Pb)
C) (²¹⁸Po)
D) (²²⁶Ra)
E) (²¹⁴U)
​

Question 17

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 18

What is the charge of a positron?

A) 1
B) 2
C) 0
D) -1
E) −2

Question 19

Arrange the following types of radiation from least penetrating to most penetrating: α,β,or γ.

A) α < b < g
B) β < g < a
C) γ < b < a
D) α < g < b
E) β < a < g

Question 20

If astatine-207 decays by two α emission followed by an electron capture,what is the product nucleus? (Atomic number of astatine = 85)

A)
B)
C)
D)
E)

Question 21

Radioactive isotopes that sit above the band of stability (n/p >>1)are most likely to decay by what mode(s)?

A) Beta emission
B) Positron emission or electron capture
C) Alpha emission
D) Electron capture or beta emission
E) Positron emission or alpha emission

Question 22

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) 0.447 g/mol
E) 0.142 g/mol

Question 23

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

A) beta emission
B) gamma emission
C) neutron emission
D) alpha emission
E) positron emission

Question 24

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 25

Which of the following processes is responsible for the change of uranium-235 to thorium-231?

A) α particle emission
B) β particle emission
C) Positron emission
D) Electron capture
E) Neutron capture

Question 26

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

A)
B)
C)
D)
E)

Question 27

The half-life of ⁴²K is 12.5 h.How much will remain after 87 h if the original sample contained 256 g of ⁴²K?

A) 23 g
B) 2.1 g
C) 18 g
D) 19 g
E) 14 g

Question 28

Select the correct balanced reaction for the decay of barium-127 by positron emission.

A)
B)
C)
D)
E)

Question 29

The gold-197 nucleus has a binding energy per nucleon of J.Determine the difference in mass between one mole of gold-197nuclei and the component nucleons of which it is made.​

A) 1.63 × 10^-3 kg
B) 4.2 × 10^-8 kg
C) 8.27 × 10^-6 kg
D) 2.43 × 10^-10 kg
E) ​6.54 × 10^-4 kg

Question 30

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

A) α particle emission
B) β particle emission
C) Positron emission
D) Electron capture
E) Neutron capture

Question 31

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

A)
B)
C)
D)
E)

Question 32

When undergoes a beta emission,what is the product nucleus?

A)
B)
C)
D)
E)

Question 33

All isotopes with atomic number greater than _____ are unstable and radioactive.

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

Question 34

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

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

Question 35

What is the nuclear binding energy per nucleon of a nucleus? (c = 3.00 × 10⁸ m/s,1 amu = 1.66054 × 10^-27 kg) Particle
Mass (amu) 65.9260355855 1.00728 1.00867

A) 1.51 × 10^-10 kg
B) 1.49 × 10^-10 kg
C) 1.37 × 10^-12 kg
D) 6.99 × 10^-11 kg
E) 8.35 × 10^-11 kg

Question 36

A certain radioactive isotope has a rate constant of decay of 2.90 × 10^-2 min^-1.Calculate the time required for a sample of this isotope to decay to one-fourth of its initial value.

A) 23.9 min
B) 29.9 min
C) 0.0580 min
D) 47.8 min
E) 2.90 min

Question 37

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 × 10⁸ m/s)

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

Question 38

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 39

If a tree dies and the trunk remains undisturbed for 13845 years,what percentage of original is still present? (half-life of = 5730 years)

A) 37.0%
B) 28.0%
C) 81.0%
D) 19.0%

Question 40

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

A) 6.25%
B) 25%
C) 12.5%
D) 3.13%
E) 75.0%

Question 41

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 9.2 disintegrations per second?

A) 91 years
B) 67 years
C) 46 years
D) 54 years
E) 78 years

Question 42

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

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

Question 43

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 44

One way of enriching the percentage of uranium-235 for use as a nuclear fuel is _____.

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

Question 45

¹⁹F undergoes an (n,γ)reaction.What is the product of this reaction?

A) (¹⁸F)
B) (²⁰F)
C) (¹⁹Ne)
D) (¹⁹O)
E) (¹⁸Ne)

Question 46

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

A)
B)
C)
D)
E)

Question 47

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

A) Propagation,equilibration,and termination
B) Propagation,oxidation,and equilibration
C) Equilibration,propagation,and termination
D) Initiation,oxidation,and propagation
E) Initiation,propagation,and termination

Question 48

The rate constant for the decay of a radioactive isotope is 4.234 × 10^-3/day.What is the half-life of this isotope?

A) 327.4 days
B) 409.2 days
C) 81.84 days
D) 163.7 days
E) None of these

Question 49

Complete the following fusion reaction: + → _____ +

A)
B)
C)
D)
E)

Question 50

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 51

Complete the following fusion reaction.

A)
B)
C)
D)
E)

Question 52

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

A) 7.0 × 10⁵ yr
B) 1.0 × 10⁶ yr
C) 4.7 × 10⁹ yr
D) 4.9 × 10⁹ yr
E) 7.0 × 10⁹ yr

Question 53

Complete the following fission reaction:

A)
B)
C)
D)
E)

Question 54

A 4.50 mg sample of a newly discovered radioactive nucleus was analyzed and found to contain only 3.25 mg after a period of 32.1 h.What is the half-life of the nucleus?

A) 75.4 h
B) 68.4 h
C) 74.0 h
D) 12.4 h
E) 18.7 h

Question 55

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

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

Question 56

A sample of a radioactive isotope is found to have lost 26.6% of its original activity after 3.21 days.What is the rate constant for decay of this isotope?

A) 0.096 d−1
B) 0.413 d−1
C) 0.993 d−1
D) 0.0735 d−1
E) 1.34 d−1

Question 57

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 58

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 59

A radioactive isotope undergoes a positron emission.After 2.00 h,6.320% of the initial amount of the isotope remains undecayed.What is the half-life of this isotope?

A) 45.0 min
B) 30.1 min
C) 90.0 min
D) 15.0 min
E) 60.0 min

Question 60

Which of the following sets of nuclei is the most commonly used fissionable isotopes in nuclear reactors?

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

Question 61

What is the most abundant element in the human body?

A) carbon
B) hydrogen
C) calcium
D) oxygen
E) water

Question 62

The becquerel is an SI unit for the measurement of radiation.1 Bq represents _____.

A) 1 J energy absorbed per kg of tissue
B) 3.7 × 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 63

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

Question 64

Which of the following isotopes is used in the medical diagnosis of thyroid disorders?

A)
B)
C)
D)
E)

Question 65

What is the most abundant element on the earth (including the crust,oceans,and atmosphere)?

A) silicon
B) oxygen
C) hydrogen
D) carbon
E) iron

Question 66

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

Question 67

The symbol for the element boron is

A) B
B) Bn
C) Be
D) Bor
E) Bm

Question 68

The symbol for the element titanium is

A) T
B) Tt
C) Ti
D) Tm
E) Tn

Question 69

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

A) Beta particles
B) Alpha particles
C) Gamma rays
D) Low energy protons
E) Low energy neutrons

Question 70

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

Question 71

At high temperatures in fusion reactions,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 72

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 73

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

Question 74

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 75

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 76

A 0.20-mL sample of a solution containing that produces 3.7 × 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) ​0.6 L
C) ​12 mL
D) ​119 mL
E) ​none of these

Question 77

The symbol for the element iodine is

A) Io
B) In
C) Id
D) I
E) Ie

Question 78

Biological damage is quantified in a unit called the _____.

Question 79

The symbol for the element calcium is

A) Ca
B) Co
C) Cu
D) C
E) Cl

Question 80

The symbol for the element zinc is

A) Zn
B) Z
C) Zi
D) Zc
E) Zin