Question 1

Which of the following isotopes is most likely to be unstable?

Accepted Answer

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

Question 2

An 85-kg person exposed to barium-141 receives 2.5 * 105 $\beta$particles, each with an energy of 5.2 *10¯13 J. How many rads does the person receive?

Accepted Answer

A)  2.4 *10¯20 
B)  1.5 * 10¯7 
C)  1.8 * 10¯16 
D)  6.1 *10¯15 
E)  None of these choices is correct. 
A)  2.4 *10¯20 
B)  1.5 * 10¯7 
C)  1.8 * 10¯16 
D)  6.1 *10¯15 
E)  None of these choices is correct.

Question 3

After 4 half-lives, the fraction of a radioactive isotope which still remains is approximately one-eighth.

Accepted Answer

A) True 
 B)False

Question 4

The r-process occurs during supernova explosions.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following series of radioactive decays would convert Pa-234 to Ra-226?

Accepted Answer

A)  beta, alpha, beta 
B)  alpha, alpha 
C)  beta, alpha, alpha, beta 
D)  beta, alpha, alpha 
E)  alpha, beta, gamma 
A)  beta, alpha, beta 
B)  alpha, alpha 
C)  beta, alpha, alpha, beta 
D)  beta, alpha, alpha 
E)  alpha, beta, gamma

Question 6

A scintillation counter

Accepted Answer

A)  measures the signal coming from an ionized gas. 
B)  measures light emissions from excited atoms. 
C)  depends on an avalanche of electrons generated as a particle moves through a tube of argon gas. 
D)  detects high energy radiation better than low energy radiation. 
E)  detects an electric current in a gas. 
A)  measures the signal coming from an ionized gas. 
B)  measures light emissions from excited atoms. 
C)  depends on an avalanche of electrons generated as a particle moves through a tube of argon gas. 
D)  detects high energy radiation better than low energy radiation. 
E)  detects an electric current in a gas.

Question 7

Which of the following isotopes is most likely to be unstable?

Accepted Answer

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

Question 8

Cesium-134 is a $\beta$ emitter with a half-life of 2.0 years. How much of a 2.50-g sample of cesium-134 will remain after 10 years?

Accepted Answer

A)  0.0024 g 
B)  0.078 g 
C)  0.25 g 
D)  0.50 g 
E)  None of these choices is correct. 
A)  0.0024 g 
B)  0.078 g 
C)  0.25 g 
D)  0.50 g 
E)  None of these choices is correct.

Question 9

What features do the r- and s-processes for element formation have in common? How do they differ?

Accepted Answer

Both involve neutron absorption by a nuc

Question 10

Assuming that no other particles are produced, which of the following particles could be used to bombard nitrogen-14 in order to make fluorine-18?

Accepted Answer

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

Question 11

Which one of the following descriptions relating to nuclear reactions is correct?

Accepted Answer

A)  The ratio of neutrons to protons remains constant. 
B)  The number of protons plus neutrons remains constant. 
C)  The number of electron remains constant. 
D)  The total charge changes. 
E)  The total number of nucleons changes. 
A)  The ratio of neutrons to protons remains constant. 
B)  The number of protons plus neutrons remains constant. 
C)  The number of electron remains constant. 
D)  The total charge changes. 
E)  The total number of nucleons changes.

Question 12

Select the nuclide that completes the following nuclear reaction:

Accepted Answer

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

Question 13

Which one of the following nuclei has a magic number of neutrons and/or protons?

Accepted Answer

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

Question 14

Write a complete, balanced equation to represent the electron capture decay of argon-37.

Accepted Answer

The answer of Write a complete, balanced equation to represent...

Question 15

Calcium-39 undergoes positron decay. Each positron carries 5.49 MeV of energy. How much energy will be emitted when 0.0025 mol of calcium-39 decays?

Accepted Answer

A)  13.2 kJ 
B)  1.32 * 104 kJ 
C)  1.32 *106 kJ 
D)  1.32 * 109 kJ 
E)  None of these choices is correct. 
A)  13.2 kJ 
B)  1.32 * 104 kJ 
C)  1.32 *106 kJ 
D)  1.32 * 109 kJ 
E)  None of these choices is correct.

Question 16

All the disintegrations of a sample of an unknown nuclide weighing 4.6 *10¯2 g were counted. In the first half-life of the sample, the total number of disintegrations counted was 4.3 *1020. What is the atomic weight of the unknown element?

Accepted Answer

A)  32 amu 
B)  16 amu 
C)  8 amu 
D)  4 amu 
E)  None of these choices is correct. 
A)  32 amu 
B)  16 amu 
C)  8 amu 
D)  4 amu 
E)  None of these choices is correct.

Question 17

The radioisotope   will decay through

Accepted Answer

A)  ($\alpha$ decay.) 
B)  ($\beta$decay.) 
C)  ($\gamma$ decay.) 
D)  electron capture. 
E)  spontaneous fission. 
A)  ($\alpha$ decay.) 
B)  ($\beta$decay.) 
C)  ($\gamma$ decay.) 
D)  electron capture. 
E)  spontaneous fission.

Question 18

An isotope with a high value of N/Z will tend to decay through

Accepted Answer

A)  ($\alpha$ decay.) 
B)  ($\beta$ decay.) 
C)  positron decay. 
D)  electron capture. 
E)  ($\gamma$ decay.) 
A)  ($\alpha$ decay.) 
B)  ($\beta$ decay.) 
C)  positron decay. 
D)  electron capture. 
E)  ($\gamma$ decay.)

Question 19

The isotopes   are all stable, while   is radioactive. The mode of decay for   is most likely to be

Accepted Answer

A)  positron decay. 
B) ($\alpha$ decay.) 
C)  ($\gamma$decay.) 
D)  electron capture. 
E)  ($\beta$ decay.) 
A)  positron decay. 
B) ($\alpha$ decay.) 
C)  ($\gamma$decay.) 
D)  electron capture. 
E)  ($\beta$ decay.)

Question 20

Palladium-107 undergoes $\beta$decay (t1/2 = 6.5 *105 yr) to form silver-107. How long will it take for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107?

Accepted Answer

A)  2.0 *107 y 
B)  1.4 * 107 y 
C)  1.2 * 106 y 
D)  8.3 * 105 y 
E)  1.2 * 105 y 
A)  2.0 *107 y 
B)  1.4 * 107 y 
C)  1.2 * 106 y 
D)  8.3 * 105 y 
E)  1.2 * 105 y

Exam 24: Nuclear Reactions and Their Applications

Which of the following isotopes is most likely to be unstable?

An 85-kg person exposed to barium-141 receives 2.5 * 105 β\betaβ particles, each with an energy of 5.2 *10¯13 J. How many rads does the person receive?

After 4 half-lives, the fraction of a radioactive isotope which still remains is approximately one-eighth.

The r-process occurs during supernova explosions.

Which of the following series of radioactive decays would convert Pa-234 to Ra-226?

A scintillation counter

Which of the following isotopes is most likely to be unstable?

Cesium-134 is a β\betaβ emitter with a half-life of 2.0 years. How much of a 2.50-g sample of cesium-134 will remain after 10 years?

What features do the r- and s-processes for element formation have in common? How do they differ?

Assuming that no other particles are produced, which of the following particles could be used to bombard nitrogen-14 in order to make fluorine-18?

Which one of the following descriptions relating to nuclear reactions is correct?

Select the nuclide that completes the following nuclear reaction:

Which one of the following nuclei has a magic number of neutrons and/or protons?

Write a complete, balanced equation to represent the electron capture decay of argon-37.

Calcium-39 undergoes positron decay. Each positron carries 5.49 MeV of energy. How much energy will be emitted when 0.0025 mol of calcium-39 decays?

All the disintegrations of a sample of an unknown nuclide weighing 4.6 *10¯2 g were counted. In the first half-life of the sample, the total number of disintegrations counted was 4.3 *1020. What is the atomic weight of the unknown element?

The radioisotope will decay through

An isotope with a high value of N/Z will tend to decay through

The isotopes are all stable, while is radioactive. The mode of decay for is most likely to be

Palladium-107 undergoes β\betaβ decay (t1/2 = 6.5 *105 yr) to form silver-107. How long will it take for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107?

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Filters

An 85-kg person exposed to barium-141 receives 2.5 * 10⁵ $\beta$ particles, each with an energy of 5.2 *10¯¹³ J. How many rads does the person receive?

Cesium-134 is a $\beta$ emitter with a half-life of 2.0 years. How much of a 2.50-g sample of cesium-134 will remain after 10 years?

All the disintegrations of a sample of an unknown nuclide weighing 4.6 10¯² g were counted. In the first half-life of the sample, the total number of disintegrations counted was 4.3 10²⁰. What is the atomic weight of the unknown element?

Palladium-107 undergoes $\beta$ decay (t_1/2 = 6.5 *10⁵ yr) to form silver-107. How long will it take for 0.150 mol of silver-107 to form from 1.25 mol of palladium-107?