Ch.19 - Nuclear ChemistrySee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Radioactive reactions deal with the chemical instability of the nucleus in an atom. 

Nuclear Reactions

Heavy (large atomic mass) elements undergo radioactive reactions in order to increase the stability of their nuclei. 

Concept #1: Understanding Nuclear Reactions. 

In a typical stoichiometric reaction we begin with elements as reactants and end with the same elements in different forms as products. 

In a nuclear reaction the number of protons in an element are affected and so the identity of the element changes. 

The three most common types of radioactive reactions are alpha decay or capture, beta decay or capture and gamma emission

Concept #2: Types of Nuclear Reactions. 

In a radioactive decay or emission reaction the radioactive particle is ejected from the nucleus and forms a product.  

In a radioactive capture or absorption reaction the radioactive particle is taken into the element and so is seen as a reactant. 

Alpha Decay

An alpha particle is comprised of 2 protons and 2 neutrons. 

Concept #3: Understanding Alpha Decay or Emission.

An alpha decay or alpha emission occurs when an unstable nucleus ejects an alpha particle to create a new element. 

Concept #4: The Alpha Particle. 

The alpha particle is one of the largest radioactive particles with the highest ionizing power, but lowest penetrating power. 

Example #1: Write balanced nuclear equations for each of the following alpha emissions.

a) Curium (Cm) – 248

b) Bismuth (Bi) – 207 

Beta Decay

A beta particle has no atomic mass and is represented by an electron. 

Concept #5: Understanding Beta Decay or Emission. 

A beta decay or beta emission occurs when an unstable nucleus ejects a beta particle to create a new element. 

Concept #6: The Beta Particle. 

Beta particles are smaller in size, and therefore have more penetrating power. Luckily, they are less radioactively damaging because of their lower ionizing power. 

Example #2: Write balanced nuclear equations for each of the following beta emissions.

a) Magnesium (Mg) – 25

b) Ruthenium (Ru) – 102 

Example #3: Pb – 208 is formed from Th -232. How many alpha and beta decays have occurred?

  1. 6, 2
  2. 6, 6
  3. 6, 4
  4. 4, 6
  5. 8, 2
Gamma Emission

A gamma particle has no atomic mass and no atomic number and is represented by the sign gamma. 

Concept #7: Understanding Gamma Radiation. 

Gamma radiation is involved in the electromagnetic spectrum. Gamma rays possess the highest energy, while radio waves have lowest energy in terms of the spectrum.  

Concept #8: The Gamma Particle.

The gamma particle does not create a new element like the other radioactive particles, but instead causes the excitation of electrons within an element. 

Gamma Particles have lowest ionizing power, but are the most dangerous because of their highest penetrating power. 

Example #4: Which of the following represents an element that has experienced a gamma emission?

  1. Cl: 1s22s22p63s23p5
  2. Be: 1s22s2
  3. Na: 1s22s22p63p1
  4. N: 1s22s22p3
Electron Capture

Concept #9: Understanding Electron Capture. 

In an electron capture or electron absorption reaction our electron particle is a reactant and not a product. 

Example #5: Write balanced nuclear equations for each of the following elements after undergoing electron capture.


a) Rutherfordium (Rf) – 263

b) Nobelium (No) – 260

c) Lead (Pb) – 207

Positron Emission

A positron particle is referred to as the anti-electron particle because it looks like a positively charged electron. 

Concept #10: Understanding Positron Emission. 

A positron decay or positron emission occurs when an unstable nucleus ejects a positron particle to create a new element. 

Example #6: Write balanced nuclear equations for each of the following positron emissions.

a) Uranium (U) – 235

b) Radon (Rn) – 222 

Example #7: A nuclide of Th-225 undergoes 3 alpha decays, 4 beta decays, and a gamma emission. What is the product?

a.  Radium

b.  Radon

c.   Actinium

d.  Cadmium

e.   Antimony 

Additional Problems
Uranium-238 decays spontaneously by consecutive emissions into what is believed to be a different uranium isotope. What series of emissions has most likely occurred? (a) alpha, beta, alpha (b) alpha, beta, beta (c) beta, beta, beta (d) alpha, beta, gamma (e) it is not possible for one uranium isotope to decay into another
Which one of the following forms of radiation can penetrate the deepest into body tissue? a) alpha (b) beta (c) gamma (d) positron (e) proton
Americium-241 is used in a number of smoke detectors; as this radioisotope decays it causes particles to ionize, conduct an electric current and thereby cause the alarm to buzz. The complete decay of Am 241 involves (successively) α, α, β, α, α, β, α, α, α, β, α and β production.    1. The isotope that undergoes the first β particle emission is: a) U-233   b) Pa-233 c) Pa-239 d) Am-241       2. The isotope obtained when Am-241 has completed this decay sequence is: a) Pb-208 b) Re-205 c) Bi-209 d) Au-209  
In the 232Th decay series, there are six α particles and four β particles lost. What is the final product?   a) 207Pb b) 208Pb c) 210Po d) 206Pb e) 210Bi
Technetium-97 can be produced by absorption of 2H and emission of two neutrons. What is the starting nuclide?   a) 97Mo b) 98Ru c) 97Ru d) 96Nb e) 96Mo 
The thorium-232 decay series begins with the emission of an alpha particle. If the daughter decays by beta emission, what is the resulting nuclide?
Complete these nuclear reactions.
Write a nuclear equation for the indicated decay of each of the following nuclides. Express your answer as a nuclear equation.Ra−210 (alpha)Sn−126 (beta)Th−234 (beta)Mn−49 (positron emission)Ar−37 (electron capture)
What is the daughter nucleus produced a. when 217(At) undergoes alpha decay?b. when 103(Mo) undergoes beta decay?c. when 188(Hg) undergoes positron emission?
Complete these nuclear reactions.
Match the characteristics with the correct type of radiation:
Write a nuclear equation for the indicated decay of each of the following nuclides. Express each as a nuclear equation.a. Po-210 (alpha)b. Ac-227 (beta)c. Th-234 (beta)d. O-15 (positron emission)e. Pd-103 (electron capture)
How does a nuclear reaction differ from a chemical reaction?a. In a nuclear reaction, the elements change identities while in a chemical reaction they do not.b.  Entropy is increased in a chemical reaction while it is decreased in a nuclear reaction.c. There is no actual difference between the two reactions except that a nuclear reaction emits radiation while a chemical reaction emits heat.d. Entropy is increased in a nuclear reaction while it is decreased in a chemical reaction.e. In a chemical reaction, elements are created and destroyed while all elements are conserved in a nuclear reaction.
Using general tendencies, predict the most likely mode of decay of each of the following radioactive isotopes.( α decay , β decay, e emission, e capture)1. iodine-1372. sodium - 203. thorium- 2324. mercury- 1905. potassium- 47
Identify the product of radioactive decay.Identify the product of radioactive decay and classify the given nuclear reaction accordingly.Drag the appropriate items to their respective bins.
Fill in the blanks in the partial decay series. Express your answers as a chemical expression.
Complete and balance the following nuclear equations. Express your answer as a nuclear equation.
What is the activity of a 45.9 mu Ci sample of carbon-14 in becquerels?