Question 1

The half-life of 90Sr is 29 years. What fraction of the atoms in a sample of 90Sr would remain 175 years later?

Accepted Answer

A) 0.17 
B) 0.12 
C) 0.062 
D) 0.015 
E) 0.50 
A) 0.17 
B) 0.12 
C) 0.062 
D) 0.015 
E) 0.50 D

Question 2

In the following reaction, identify X.

Accepted Answer

A) ($\alpha$) 
B) n 
C) p 
D)    
E) ($\beta$) 
A) ($\alpha$) 
B) n 
C) p 
D)    
E) ($\beta$) B

Question 3

Decay of lutetium-167 by electron capture yields

Accepted Answer

A) ytterbium-167. 
B) lutetium-166. 
C) thulium-163. 
D) tantalum-171. 
E) hafnium-167. 
A) ytterbium-167. 
B) lutetium-166. 
C) thulium-163. 
D) tantalum-171. 
E) hafnium-167. A

Question 4

Gamma-rays cause radiation damage when they interact with matter by producing

Accepted Answer

A) ions and free radicals. 
B) isotopes. 
C) daughter products. 
D) oxidation. 
E) reduction. 
A) ions and free radicals. 
B) isotopes. 
C) daughter products. 
D) oxidation. 
E) reduction.

Question 5

Strontium-90 has a half-life of 28.8 years. How much strontium-90 was present initially, if after 144 years 10.0 g remain?

Accepted Answer

The answer of Strontium-90 has a half-life of 28.8 years....

Question 6

Predict which nucleus is less stable,   or   .

Accepted Answer

The answer of Predict which nucleus is less stable, ...

Question 7

A plot of the number of neutrons versus the number of protons in various isotopes produces a "belt of stability." Isotopes below the belt of stability (i.e., with a smaller neutron-to-proton ratio)decay by beta particle emission.

Accepted Answer

A) True 
 B)False

Question 8

Sulfur-35 decays by beta emission. The decay product is

Accepted Answer

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

Question 9

Balance the equation   .

Accepted Answer

The answer of Balance the equation   ....

Question 10

Calculate the binding energy per nucleon of an Al-27 nucleus given the following masses:   : 26.981541 amu;   : 1.007838 amu;   : 1.008665 amu.

Accepted Answer

1.34 * 10<

Question 11

When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also formed?

Accepted Answer

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

Question 12

How many 14C atoms are in a charcoal sample that has a decay rate of 3,500 disintegrations per min? (For 14C, t1/2 = 5,730 yr.)

Accepted Answer

A) 2.9 * 107 atoms 
B) 8.0 * 10-7 atoms 
C) 1.4 * 1014 atoms 
D) 1.5 * 1013 atoms 
E) 6.02 * 1020 atoms 
A) 2.9 * 107 atoms 
B) 8.0 * 10-7 atoms 
C) 1.4 * 1014 atoms 
D) 1.5 * 1013 atoms 
E) 6.02 * 1020 atoms

Question 13

The dose unit of ionizing radiation is called the rad. The rad is defined in terms of

Accepted Answer

A) the half-life of a radioisotope. 
B) the energy deposited per gram of an object. 
C) the biological damage produced. 
D) the accumulation of fission products. 
E) the number of ions per centimeter. 
A) the half-life of a radioisotope. 
B) the energy deposited per gram of an object. 
C) the biological damage produced. 
D) the accumulation of fission products. 
E) the number of ions per centimeter.

Question 14

Balance the equation   .

Accepted Answer

The answer of Balance the equation   ....

Question 15

The only stable isotope of iodine is iodine-127. Predict the mode of decay of   .

Accepted Answer

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

Question 16

Protactinium-234 has a half-life of 1 minute. How much of a 400. g sample protactinium would remain after 1 minute?

Accepted Answer

The answer of Protactinium-234 has a half-life of 1 minute....

Question 17

Alpha particles are identical to

Accepted Answer

A) protons. 
B) helium atoms. 
C) hydrogen atoms. 
D) helium nuclei. 
E) electrons. 
A) protons. 
B) helium atoms. 
C) hydrogen atoms. 
D) helium nuclei. 
E) electrons.

Question 18

The energy released by the sun is the result of

Accepted Answer

A) natural radioactivity. 
B) nuclear fusion. 
C) combustion of hydrogen. 
D) photosynthesis. 
E) nuclear fission. 
A) natural radioactivity. 
B) nuclear fusion. 
C) combustion of hydrogen. 
D) photosynthesis. 
E) nuclear fission.

Question 19

Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original sample of 2.00 mg will remain after 8.00 years?

Accepted Answer

A) 0.147 mg 
B) 0.296 mg 
C) 0.725 mg 
D) 6.77 mg 
E) 1.90 mg 
A) 0.147 mg 
B) 0.296 mg 
C) 0.725 mg 
D) 6.77 mg 
E) 1.90 mg

Question 20

Rubidium-87 decays by beta decay with a half-life of 4.9 * 1010 yr. How many 87Rb atoms are in a moon rock sample that has a rubidium decay rate of 3,500 disintegrations per hour?

Accepted Answer

A) 9.0 * 1016 atoms 
B) 4.3 * 10-4 atoms 
C) 2.2 * 1018 atoms 
D) 2.5 * 1014 atoms 
E) 1.7 * 1014 atoms 
A) 9.0 * 1016 atoms 
B) 4.3 * 10-4 atoms 
C) 2.2 * 1018 atoms 
D) 2.5 * 1014 atoms 
E) 1.7 * 1014 atoms

Exam 21: Nuclear Chemistry

The half-life of 90Sr is 29 years. What fraction of the atoms in a sample of 90Sr would remain 175 years later?

In the following reaction, identify X.

Decay of lutetium-167 by electron capture yields

Gamma-rays cause radiation damage when they interact with matter by producing

Strontium-90 has a half-life of 28.8 years. How much strontium-90 was present initially, if after 144 years 10.0 g remain?

Predict which nucleus is less stable, or .

A plot of the number of neutrons versus the number of protons in various isotopes produces a "belt of stability." Isotopes below the belt of stability (i.e., with a smaller neutron-to-proton ratio)decay by beta particle emission.

Sulfur-35 decays by beta emission. The decay product is

Balance the equation .

Calculate the binding energy per nucleon of an Al-27 nucleus given the following masses: : 26.981541 amu; : 1.007838 amu; : 1.008665 amu.

When atoms of beryllium-9 are bombarded with alpha particles, neutrons are produced. What new isotope is also formed?

How many 14C atoms are in a charcoal sample that has a decay rate of 3,500 disintegrations per min? (For 14C, t1/2 = 5,730 yr.)

The dose unit of ionizing radiation is called the rad. The rad is defined in terms of

Balance the equation .

The only stable isotope of iodine is iodine-127. Predict the mode of decay of .

Protactinium-234 has a half-life of 1 minute. How much of a 400. g sample protactinium would remain after 1 minute?

Alpha particles are identical to

The energy released by the sun is the result of

Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original sample of 2.00 mg will remain after 8.00 years?

Rubidium-87 decays by beta decay with a half-life of 4.9 * 1010 yr. How many 87Rb atoms are in a moon rock sample that has a rubidium decay rate of 3,500 disintegrations per hour?

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Organic Polymerssynthetic and Natural

Filters

The half-life of ⁹⁰Sr is 29 years. What fraction of the atoms in a sample of ⁹⁰Sr would remain 175 years later?

How many ¹⁴C atoms are in a charcoal sample that has a decay rate of 3,500 disintegrations per min? (For ¹⁴C, t_1/2 = 5,730 yr.)

Rubidium-87 decays by beta decay with a half-life of 4.9 * 10¹⁰ yr. How many ⁸⁷Rb atoms are in a moon rock sample that has a rubidium decay rate of 3,500 disintegrations per hour?