Question 1

Which of the following statements about positrons is false?

Accepted Answer

A) The positron has same mass as an electron. 
B) A positron is ejected from the nucleus during the conversion of a proton into a neutron. 
C) A positron is a positive electron. 
D) When positron emission occurs,the atomic number of the nucleus increases. 
A) The positron has same mass as an electron. 
B) A positron is ejected from the nucleus during the conversion of a proton into a neutron. 
C) A positron is a positive electron. 
D) When positron emission occurs,the atomic number of the nucleus increases. D

Question 2

The practical limit for 14C dating occurs when its activity falls to 0.20% of its original value due to interference in detectors by natural background radiation.If the half-life is 5715 years,what is the maximum age of a sample that can be dated by 14C without interference?

Accepted Answer

A) 1.3 × 104 years 
B) 2.9 × 104 years 
C) 5.1 × 104 years 
D) 2.9 × 106 years 
A) 1.3 × 104 years 
B) 2.9 × 104 years 
C) 5.1 × 104 years 
D) 2.9 × 106 years C

Question 3

Iodine-123,used in thyroid therapy,has a half-life of 13.27 hours.How many half-lives are required for a 160 mg sample of iodine-123 to decay to 5.0 mg?

Accepted Answer

A) 0.031 
B) 1.0 
C) 5.0 
D) 32 
A) 0.031 
B) 1.0 
C) 5.0 
D) 32 C

Question 4

In an electron capture reaction a proton is converted into a ________.

Accepted Answer

The answer of In an electron capture reaction a proton...

Question 5

Which of the following elements would be expected to be particularly stable?

Accepted Answer

A)   
Ca 
B)   
K 
C)   
Ar 
D)   
Cl 
A)   
Ca 
B)   
K 
C)   
Ar 
D)   
Cl

Question 6

Which of the following reactions correctly shows the transmutation of an element by neutron absorption followed by beta emission?

Accepted Answer

A)   
Tl +
  
N →
  
E +
  
Pb 
B)   
Tl +
  
E →
  
N +
  
Dy 
C)   
I +
  
N →
  
E +
  
Xe 
D)   
Ce +
  
E →
  
N +
  
La 
A)   
Tl +
  
N →
  
E +
  
Pb 
B)   
Tl +
  
E →
  
N +
  
Dy 
C)   
I +
  
N →
  
E +
  
Xe 
D)   
Ce +
  
E →
  
N +
  
La

Question 7

What is needed to balance the nuclear transmutation reaction below?   Am →   Np + ?

Accepted Answer

The answer of What is needed to balance the nuclear...

Question 8

Which of the following statements about gamma radiation is false?

Accepted Answer

A) It almost always accompanies alpha or beta emission. 
B) It is a mechanism to release excess energy in the nucleus. 
C) Gamma rays are high energy photons. 
D) The mass number decreases by one with each gamma emitted. 
A) It almost always accompanies alpha or beta emission. 
B) It is a mechanism to release excess energy in the nucleus. 
C) Gamma rays are high energy photons. 
D) The mass number decreases by one with each gamma emitted.

Question 9

In the transmutation reaction that results in the formation of berkelium-243,shown below,the nucleus that is bombarded by alpha particles is ________.
? +   He →   Bk + 2   n

Accepted Answer

The answer of In the transmutation reaction that results in...

Question 10

The decay constant,k,is given for each of the beta emitters below.Which one has the shortest half life?

Accepted Answer

A) .115In,4.29 × 10-9 s-1 
B) .131I,9.94 × 10-7 s-1 
C) .217At,21.4 s-1 
D) .42K,1.55 × 10-5 s-1 
A) .115In,4.29 × 10-9 s-1 
B) .131I,9.94 × 10-7 s-1 
C) .217At,21.4 s-1 
D) .42K,1.55 × 10-5 s-1

Question 11

Which reaction below represents   Ti decay by electron capture?

Accepted Answer

A)   
Ti +
  
E →
  
Ti 
B)   
Ti +
  
E →
  
Ti 
C)   
Ti +
  
E →
  
Ti 
D)   
Ti +
  
E →
  
Sc 
A)   
Ti +
  
E →
  
Ti 
B)   
Ti +
  
E →
  
Ti 
C)   
Ti +
  
E →
  
Ti 
D)   
Ti +
  
E →
  
Sc

Question 12

What is the abbreviation used for the curie,a unit used in the measurement of nuclear disintegrations per unit time?

Accepted Answer

A) Cm 
B) Cb 
C) Ci 
D) Ce 
A) Cm 
B) Cb 
C) Ci 
D) Ce

Question 13

Which unit of radiation is frequently used in medicine to describe the amount of tissue damage caused by a radioactive substance?

Accepted Answer

A) becquerel 
B) curie 
C) rad 
D) rem 
A) becquerel 
B) curie 
C) rad 
D) rem

Question 14

A shorthand way of writing transmutation equations is to show the bombarding particle and the subsequent emitted particle in parentheses.Which of the following equations shows the balanced nuclear reaction for   Li (n,α)?

Accepted Answer

A)   
Li +
  
N →
  
He +
  
H 
B)   
Li +
  
He →
  
N +
  
B 
C)   
Li +
  
N →
  
He +
  
He 
D)   
Li +
  
He →
  
N +
  
Be 
A)   
Li +
  
N →
  
He +
  
H 
B)   
Li +
  
He →
  
N +
  
B 
C)   
Li +
  
N →
  
He +
  
He 
D)   
Li +
  
He →
  
N +
  
Be

Question 15

Which statement about nuclear reactions is true?

Accepted Answer

A) New elements are never produced in a nuclear reaction. 
B) Nuclear reactions involve valence electrons. 
C) The rate of a nuclear reaction is affected by catalysts. 
D) Tremendous amounts of energy are involved in nuclear reactions. 
A) New elements are never produced in a nuclear reaction. 
B) Nuclear reactions involve valence electrons. 
C) The rate of a nuclear reaction is affected by catalysts. 
D) Tremendous amounts of energy are involved in nuclear reactions.

Question 16

What percentage of a radioactive substance remains after 6.00 half-lives have elapsed?

Accepted Answer

A) 0.78% 
B) 1.56% 
C) 3.31% 
D) 6.25% 
A) 0.78% 
B) 1.56% 
C) 3.31% 
D) 6.25%

Question 17

The term "nucleons" refers to the number of ________ in the atom.

Accepted Answer

A) neutrons and electrons 
B) electrons 
C) protons and neutrons 
D) protons and electrons 
A) neutrons and electrons 
B) electrons 
C) protons and neutrons 
D) protons and electrons

Question 18

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

Accepted Answer

A)   
Hg 
B)   
Hg 
C)   
Hg 
D)   
Hg 
A)   
Hg 
B)   
Hg 
C)   
Hg 
D)   
Hg

Question 19

The number of nucleons in a   U2+ nucleus is

Accepted Answer

A) 92. 
B) 144. 
C) 236. 
D) 328. 
A) 92. 
B) 144. 
C) 236. 
D) 328.

Question 20

Tell the type of decay process occurring in the following nuclear reaction.

Accepted Answer

A) α emission 
B) β emission 
C) γ emission 
D) electron capture or positron emission 
A) α emission 
B) β emission 
C) γ emission 
D) electron capture or positron emission

Exam 19: Nuclear Chemistry

Which of the following statements about positrons is false?

The practical limit for 14C dating occurs when its activity falls to 0.20% of its original value due to interference in detectors by natural background radiation.If the half-life is 5715 years,what is the maximum age of a sample that can be dated by 14C without interference?

Iodine-123,used in thyroid therapy,has a half-life of 13.27 hours.How many half-lives are required for a 160 mg sample of iodine-123 to decay to 5.0 mg?

In an electron capture reaction a proton is converted into a ________.

Which of the following elements would be expected to be particularly stable?

Which of the following reactions correctly shows the transmutation of an element by neutron absorption followed by beta emission?

What is needed to balance the nuclear transmutation reaction below? Am → Np + ?

Which of the following statements about gamma radiation is false?

In the transmutation reaction that results in the formation of berkelium-243,shown below,the nucleus that is bombarded by alpha particles is ________. ? + He → Bk + 2 n

The decay constant,k,is given for each of the beta emitters below.Which one has the shortest half life?

Which reaction below represents Ti decay by electron capture?

What is the abbreviation used for the curie,a unit used in the measurement of nuclear disintegrations per unit time?

Which unit of radiation is frequently used in medicine to describe the amount of tissue damage caused by a radioactive substance?

A shorthand way of writing transmutation equations is to show the bombarding particle and the subsequent emitted particle in parentheses.Which of the following equations shows the balanced nuclear reaction for Li (n,α)?

Which statement about nuclear reactions is true?

What percentage of a radioactive substance remains after 6.00 half-lives have elapsed?

The term "nucleons" refers to the number of ________ in the atom.

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

The number of nucleons in a U2+ nucleus is

Tell the type of decay process occurring in the following nuclear reaction.

Chemical Tools: Experimentation and Measurement

Atoms, molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Periodicity and the Electronic Structure of Atoms

Ionic Compounds: Periodic Trends and Bonding

Covalent Bonding and Electron-Dot Structures

Covalent Compounds: Bonding Theories and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids, solids, and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

The Main-Group Elements

Connections to Organic and Biological Chemistry

Filters

The practical limit for ¹⁴C dating occurs when its activity falls to 0.20% of its original value due to interference in detectors by natural background radiation.If the half-life is 5715 years,what is the maximum age of a sample that can be dated by ¹⁴C without interference?

The number of nucleons in a U²⁺nucleusis