Deck 20: Nuclear Chemistry

Question 1

The number of neutrons in the isotope bismuth-208 is _____.

A) 125
B) 83
C) 208
D) 124
E) 209

Answer 1

125

Question 2

Nuclear transmutation reactions occur spontaneously under all conditions.

Answer 2

False

Question 3

The daughter nuclei that result from the radioactive decay of an element are less stable than the parent nucleus.

Answer 3

False

Question 4

The isotope radium-227 has _____ protons.

A) 227
B) 89
C) 88
D) 139
E) 138

Question 5

Isotopes that emit radiation are called _____.

Question 6

Isotopes are nuclides with same number of neutrons but different numbers of protons.

Question 7

The atomic number is the number of neutrons in the nucleus of an atom.

Question 8

Any nucleus that is unstable and decays spontaneously, emitting particles and electromagnetic radiations is said to be _____.

Question 9

Define half-life of an isotope.

Question 10

The nuclear symbol for the isotope osmium-183 is _____.

A) ${ } _ { 70 } ^ { 183 }\mathrm { Os }$
B) ${ } _ { 183 } ^ { 76 }\mathrm { Os }$
C) ${ } _ { 76 } ^ { 114 }\mathrm { Os }$
D) ${ } _ { 76 } ^ { 183 }\mathrm { Os }$
E) ${ } _ { 76 } ^ { 107 } \mathrm { OS }$

Question 11

Which of the following is a stable nuclide?

A) ${ } _ { 8 } ^ { 15 } \text{O}$
B) ${ } _ { 90 } ^ { 232 } \mathrm { Th }$
C) ${ } _ { 43 } ^ { 98 } \mathrm { Tc }$
D) ${ } _ { 20 } ^ { 40 } \mathrm { Ca }$
E) ${ } _ { 15 } ^ { 30 } \mathrm { P }$

Question 12

A(n) _____ is an extremely powerful but very short-range attractive force between nucleons that keeps the nucleus of an atom from flying apart.

Question 13

An atom with a particular number of protons and neutrons is called a(n) _____.

A) element
B) nuclide
C) isotope
D) isomer
E) isobar

Question 14

Nuclei that have even number of both protons and neutrons are generally stable.

Question 15

Neutron-rich nuclei have a neutron-to-proton ratio that is too low to give a stable nucleus.

Question 16

The rate at which the radioactive decay occurs is a characteristic of the isotope.

Question 17

Which of the following is a radioactive isotope?

A) ${ } _ { 10 } ^ { 20 } \mathrm { Ne }$
B) ${ } _ { 94 } ^ { 239 } \mathrm { Pu}$
C) ${ } _ { 50 } ^ { 118 } \mathrm { Sn }$
D) ${ } _ { 20 } ^ { 40 } \mathrm { Ca }$
E) ${ } _ { 57 } ^ { 139 } \mathrm { La }$

Question 18

The neutron-to-proton ratio of the isotope potassium-39 is _____.

A) 2.05
B) 0.48
C) 1.05
D) 1.00
E) 0.95

Question 19

Nuclides with the same number of protons but different numbers of neutrons are called _____.

A) isotones
B) isotopes
C) isomers
D) isobars
E) polymers

Question 20

The protons and neutrons that make up the nucleus of an atom are called _____.

Question 21

_____ is a nuclear decay reaction that results in the emission of a helium-4 nucleus.

A) Beta decay
B) Alpha decay
C) Positron emission
D) Electron decay
E) Spontaneous emission

Question 22

Which of the following particles is emitted when ${ } ^ { 32 } \mathrm {~S} i$ undergoes radioactive decay to give ${ } ^ { 32 } \mathrm { P }$ ?

A) ${ } _ { 0 } ^ { 0 } \gamma$
B) ${ } _ { + 1 } ^ { 0 } \beta$
C) ${ } _ { 2 } ^ { 4 } \alpha$
D) ${ } _ { 1 } ^ { 0 } \mathrm { n }$
E) ${ } _ { -1 } ^ { 0 } \beta$

Question 23

Complete the balanced nuclear equation ${ } _ { 13 } ^ { 27 } \mathrm {~A} 1 + \longrightarrow { } _ { 15 } ^ { 30 } \mathrm { P } + { } _ { 0 } ^ { 1 } \mathrm { n }$ .

A) ${ } _ { 1 } ^ { 2 } \mathrm { H }$
B) ${ } _ { 1 } ^ { 3 } \mathrm { H }$
C) ${ } _ { 1 } ^ { 1 } \mathrm { p }$
D) ${ } _ { 2 } ^ { 4 } \alpha$
E) ${ } _ { + 1 } ^ { 0 } \beta$

Question 24

A nuclear decay reaction in which a proton is transformed into a neutron, and which results in lowering of the atomic number by 1 than that of the parent nucleus is known as _____. This reaction is considered the opposite of beta decay.

A) gamma emission
B) spontaneous fission
C) neutron decay
D) alpha decay
E) positron emission

Question 25

Neutron-poor nuclei are a class of radioactive nuclei that:

A) decay by a process that has the net effect of converting a proton to a neutron.
B) tend to decay by emitting an alpha particle which reduces the number of neutrons and protons in the original nucleus by 2.
C) have neutron-to-proton ratio that is too high to give a stable nucleus.
D) lie on the upper left side of the band of stable nuclei.
E) decay by a process which results in a decrease in the neutron-to-proton ratio.

Question 26

A nuclear decay reaction in which a neutron is converted to a proton and a high-energy electron and results in an increase in the atomic number by +1 is known as _____.

A) gamma ejection
B) spontaneous fission
C) beta decay
D) alpha decay
E) positron ejection

Question 27

The series of sequential alpha- and beta-decay reactions that occur until a stable nucleus is finally obtained is called a(n) _____.

Question 28

Electron capture does not change the mass number of the nucleus.

Question 29

Which of the following nuclides is most likely to undergo alpha decay?

A) ${ } _ {16 } ^ { 36 }S$
B) ${ } _ { 42 } ^ { 99 } \mathrm { Mo }$
C) ${ } _ { 92 } ^ { 235 } \mathrm { U }$
D) ${ } _ { 35 } ^ { 80 }\text { Br }$
E) ${ } _ { 37 } ^ { 87 } \mathrm { Rb }$

Question 30

A nuclear decay reaction that results when a nucleus in an excited state releases energy in the form of a high energy photon when it returns to the ground state is called _____.

A) gamma emission
B) alpha decay
C) beta decay
D) positron emission
E) spontaneous fission

Question 31

The net result of an alpha emission is an increase in the neutron-to-proton ratio.

Question 32

The balanced nuclear equation for alpha decay of ${ } ^ { 218 } \text { Po }$ is _____.

A) ${ } _ { 84 } ^ { 218 } \mathrm { Po } \rightarrow { } _ { 85 } ^ { 218 } \mathrm { At } + { } _ { - 1 } ^ { 0 } \beta$
B) ${ } _ { 84 } ^ { 218 } \mathrm { Po } \rightarrow { } _ { 80 } ^ { 212 } \mathrm { Hg } + { } _ { 4 } ^ { 2 } \alpha$
C) ${ } _ { 84 } ^ { 218 } \mathrm { Po } \rightarrow { } _ { 82 } ^ { 214 } \mathrm {~Pb} + { } _ { 2 } ^ { 4 } \alpha$
D) ${ } _ { 84 } ^ { 218 } \mathrm { Po } \rightarrow { } _ { 83 } ^ { 218 } \mathrm { Bi } + { } _ { + 1 } ^ { 0 } \beta$
E) ${ } _ { 84 } ^ { 218 } \mathrm { Po } \rightarrow { } _ { 84 } ^ { 214 } \mathrm { Bi } + { } _ { 2 } ^ { 4 } \alpha$

Question 33

A nuclear decay reaction in which an electron in an inner shell reacts with a proton to produce a neutron is called _____.

A) electron decay
B) spontaneous fission
C) gamma emission
D) electron capture
E) neutron emission

Question 34

A(n) _____ is a nuclear reaction that occurs when an unstable nucleus emits radiation and is transformed into the nucleus of one or more other elements.

Question 35

The radiation emitted when a nucleus undergoes spontaneous fission is _____.

A) ${ } _ { 0 } ^ { 0 } \gamma$
B) ${ } _ { + 1 } ^ { 0 } \beta$
C) ${ } _ { 2 } ^ { 4 } \alpha$
D) ${ } _ { 0 } ^ { 1 } n$
E) ${ } _ { -1 } ^ { 0 }\beta$

Question 36

Which of the following nuclear decay reactions involves ejection of a high-energy electron?

A) Beta decay
B) Alpha decay
C) Positron emission
D) Electron capture
E) Spontaneous emission

Question 37

A nuclear reaction in which a nucleus reacts with a subatomic particle or another nucleus to give a product nucleus that is more massive than the starting material is called a(n) _____ reaction.

A) nuclear decay
B) positron emission
C) spontaneous fission
D) nuclear transmutation
E) radioactive decay

Question 38

Write a note on the discovery of neutron by Ernest Rutherford.

Question 39

What is positron emission? Explain with an example.

Question 40

The general reaction for positron emission is _____.

A) ${ } _ { z } ^ { \mathrm { A } } \mathrm { X } \rightarrow { } _ { \mathrm { Z } + 1 } ^ { \mathrm { A } } \mathrm { X } ^ { \prime } + { } _ { - 1 } ^ { 0 } \mathrm {?}$
B) ${ } _ { Z } ^ { A } X \rightarrow { } _ { Z 2 } ^ { A4 } X ^ { \prime } + { } _ { 2 } ^ { 4 } \alpha$
C) ${ } _ { z } ^ { \mathrm { A } } \mathrm { X } \rightarrow { } _ { z \cdot 1 } ^ { \mathrm { A } } \mathrm { X } ^ { \prime } + { } _ { + 1 } ^ { 0 } \mathrm { \beta }$
D) ${ } _ { Z } ^ { A } X ^ { * + } \rightarrow { } _ { Z } ^ { A } X + { } _ { 0 } ^ { 0 } \gamma$
E) ${ } _ { z } ^ { A } X + { } _ { - 1 } ^ { 0 } e \rightarrow { } _ { z - 1 } ^ { A } X ^ { \prime } + \text{x-ray}$

Question 41

_____ are radiations of high enough energy to transfer some of it as they pass through matter to one or more atoms with which they collide.

Question 42

Alpha particles are most damaging to humans if their source is inside the body.

Question 43

_____ are low-energy radiations, most of whose energy can be absorbed when they collide with an atom in a molecule, without causing a structural or chemical change.

A) Ionizing radiations
B) Alpha particles
C) Gamma rays
D) X-rays
E) Nonionizing radiations

Question 44

An isotope that can undergo a nuclear fission reaction when bombarded with neutrons is called a(n) _____.

Question 45

A(n) _____ is an artificial element that has been prepared by bombarding suitable target nuclei with smaller particles.

Question 46

The amount of energy released during the radioactive decay of uranium-238 to thorium-234 and an alpha particle is _____ kJ/mol. (Given, the atomic mass of ${ } ^ { 238 } \mathrm { U }$ = 238.050788 amu, ${ } ^ { 234 } \mathrm { Th }$ = 234.043601 amu, and ${ } _ { 2 } ^ { 4 } \alpha$ = 4.002603 amu)

A) -4.584 × 10⁸
B) 4.120 × 10⁸
C) 4.584 × 10⁸
D) -4.270 × 10⁸
E) -4.120 × 10⁸

Question 47

A nucleus is more stable than its isolated components.

Question 48

The mass of a hydrogen atom is less than the sum of the masses of its component particles.

Question 49

As compared to nonionizing radiations, ionizing radiations are relatively low in energy.

Question 50

The effects of nonionizing radiations can be neutralized by cooling.

Question 51

Which of the following ionizing radiations have a high charge and mass and hence do not penetrate deeply into an object?

A) γ radiations
B) X-rays
C) β particles
D) α radiations
E) δ radiations

Question 52

The unit "rad" is used to describe the actual amount of tissue damage caused by a given amount of radiation.

Question 53

Because of their great penetrating ability, _____ rays are by far the most dangerous type of radiation when they come from a source outside the body.

Question 54

What are the factors that influence the effect of ionizing radiations?

Question 55

In principle, nuclear fusion can produce much more energy than nuclear fission.

Question 56

A unit that describes the actual amount of tissue damage caused by a given amount of radiation is called the _____.

A) rem
B) roentgen
C) gray
D) rad
E) sievert

Question 57

A component of background radiation that is produced by the interaction of cosmic rays with gases in the upper atmosphere is called _____.

Question 58

Heavier nuclei spontaneously undergo nuclear reactions that increase their atomic number.

Question 59

The "_____" is the most common unit used to measure the effects of radiation on biological tissues.

A) rem
B) roentgen
C) RBE
D) rad
E) sievert

Question 60

Which of the following is a unit that describes the amount of energy absorbed by dry air and measures the radiation exposure?

A) Rad
B) Gray
C) Rem
D) Roentgen
E) RBE

Question 61

Light-water reactors use unenriched uranium as a fuel.

Question 62

Which of the following nuclear reactors use water as a moderator to slow down the neutrons to initiate a chain reaction?

A) Water fused reactors
B) Light-water reactors
C) Nuclear fusion reactors
D) Heavy-water reactors
E) Liquid metal cooled reactors

Question 63

The spent fuel in a nuclear fission reactor is more radioactive than the unused fuel.

Question 64

List out the various applications of radioisotopes.

Question 65

A self-sustaining series of nuclear fission reactions is known as a _____.

Question 66

What is a nuclear chain reaction? Give an example.

Question 67

The mass defect for ${ } ^ { 29 } S$ is _____ amu. (Given, the experimentally determined mass of ${ } ^ { 29 } S$ = 28.996610 amu, mass of proton = 1.007825 amu and mass of neutron = 1.008665 amu)

A) 1.007825
B) 16.379875
C) 0.421235
D) 29.237845
E) 0.241235

Question 68

The splitting of a heavy nucleus into two lighter ones is known as _____.

A) nuclear transmutation
B) nuclear fission
C) positron emission
D) electron capture
E) nuclear fusion

Question 69

The combining of two lighter nuclei to produce a heavier, more stable nucleus is known as _____.

A) nuclear fission
B) electron capture
C) positron emission
D) spontaneous fission
E) nuclear fusion

Question 70

The amount of energy released by the neutron induced fission of ${ } ^ { 235 } \mathrm { U }$ to give ${ } ^ { 90 } \mathrm { Sr }$ , ${ } ^ { 143 } \mathrm { Xe }$ , and three neutrons is _____ MeV/atom. (Given, the experimentally determined mass of ${ } ^ { 235 } \mathrm { U }$ = 235.043930 amu, ${ } ^ { 90 } \mathrm { Sr }$ = 89.907738 amu, ${ } ^ { 143 } \mathrm { Xe }$ = 142.935110 amu, and mass of neutron = 1.008665 amu)

A) -143
B) -171
C) -183
D) -117
E) -235

Question 71

Which of the following nuclear reactors uses D₂O as a moderator?

A) Graphite Moderated reactors
B) Light-water reactors
C) Heavy-water reactors
D) nuclear fusion reactors
E) Molten salt reactors

Question 72

The components in a light-water nuclear reactor that are used to absorb neutrons and thereby control the rate of the nuclear chain reaction are called _____.

Question 73

The component of a nuclear reactor that is used to decrease the kinetic energy of neutrons by the radioactive decay of the fuel to initiate a chain reaction is called a _____.

A) condenser
B) steam generator
C) moderator
D) fuel rod
E) control rod

Question 74

The amount of energy released when a nucleus forms from its component nucleons, which corresponds to the mass defect of the nucleus is called the _____ energy.

A) bond
B) nuclear binding
C) lattice
D) ionization
E) electron binding

Question 75

Deuterium (²H) absorbs neutrons much more effectively than does hydrogen (¹H).

Question 76

The difference between the sum of the masses of the components of an atom and the measured atomic mass is called the _____ of the nucleus.

Question 77

The function of a moderator in a nuclear power reactor is to slow down the neutrons to allow them to be absorbed by other nuclei.

Question 78

The binding energy per nucleon for uranium 238 is _____ MeV/nucleon. (Given, the experimentally determined mass of ${ } ^ { 238 } \mathrm { U }$ = 238.050788 amu, mass of proton = 1.007825 amu and mass of neutron = 1.008665 amu)

A) 1.93
B) 7.57
C) 9.27
D) 1800
E) 1.48

Question 79

The minimum mass of a fissile isotope capable of supporting sustained fission is called the _____.

Question 80

The amount of energy released by the neutron induced fission of ${ } ^ { 235 } \mathrm { U }$ to give ${ } ^ { 141 } \mathrm { Ba }$ , ${ } ^ { 92 } \mathrm { Kr }$ , and three neutrons is _____ 10¹⁰ kJ/mol. (Given, the experimentally determined mass of ${ } ^ { 235 } \mathrm { U }$ = 235.043930 amu, ${ } ^ { 141 } \mathrm { Ba }$ = 140.914411 amu, ${ } ^ { 92 } \mathrm { Kr }$ = 91.926156 amu, and mass of neutron = 1.008665 amu)

A) -1.40
B) -1.67
C) -1.86
D) -1.73
E) -2.35