Nuclear chemistry notes packet

Name: ____________________ Honors Chem - Mrs. Concannon
Date: _________________
Nuclear Chemistry
Study Guidelines:
Identify the type of nuclear reactions as either natural transmutation,
artificial transmutation, fission, or fusion.
Differentiate among characteristics of emanations.
Determine decay mode and write nuclear equations showing alpha and beta decay.
Complete nuclear equations by predicting missing particles from nuclear equations.
Calculate the initial amount, the fraction remaining, or the half-life of a radioactive isotope, given
two of the three variables.
Identify specific uses of some common radioisotopes.
Compare and contrast fission and fusion reactions.
Identify parts of a fission reactor.
Compare and contrast energy changes for nuclear versus chemical reactions.
Describe how radioisotopes are used in everyday life
Essential Questions:
Why are some nuclei unstable? Is nuclear technology a benefit to society?
Vocabulary:
Isotope
Radioisotope
Emanation
Alpha particle
Beta particle
Gamma ray
Positron
X-ray
Penetrating power
Ionizing power
Spontaneous decay
Mode of decay
Natural decay
Natural transmutation
Stability
Assignments:
Read Chapter 25
Worksheets in packet
Yellow Review Book pages 65-72 and 73-74
Artificial transmutation
Fission
Fusion
Half-life
Radioactive dating
Tracing
Biological Exposure
Mutation
Bombardment
High-energy particles
Theory of Relativity
biological exposure
mutation
long-term storage and disposal
nuclear accidents
Quizzes
1) Writing Nuclear Reactions
2) Half life problems
3) Identifying nuclear reactions and parts of the reactor
radioactive dating - C14 to
C12 ratio, U-238 to Pb-206
tracing chemical and
biological processes
industrial measurement
nuclear power
detection and treatment of
diseases - I-131 and Co-60
coolant
moderator
shielding
fuel rod
control rod
fusion

Nuclear Chemistry
Definition – the study of the structure and changes within the nucleus of an atom. These
changes may affect the stability of the nucleus.
Difference from chemical changes – new elements form as a result of nuclear changes.
Review:
Nuclear radiation – Emanations
Particles and rays that come from radioactive material.
See Table O
Emanation
Alpha
Notation Mass Charge Ionizing
power
Beta
Positron
Gamma
Penetrating
power
Unstable nuclei – some nuclei breakdown spontaneously to different products because of
ratio of protons to neutrons.
Isotope – form of an element with the same atomic # but different atomic mass.
Radioisotopes – isotopes of atoms with unstable nuclei.
What holds Nucleus together – Though protons are positive and should repel each other
neutrons are neutral. All are called nucleons and are held together by another force called the
strong nuclear force. This however, only works over a short distance and while the neutrons
help balance the protons repulsive affect as the number of protons grows the ratio of protons
to neutrons becomes important. All elements over atomic# 83 are unstable. Ratios between
1.5-1.0 and 1.0-1.0 are considered stable.

Radioactive Decay – During radioactive decay unstable nuclei breakdown and
spontaneously emit some types of radiation.
Types of Decay
Writing Nuclear Equations:
Nuclear equations use symbols to identify the atomic nuclei and radiation involved. These
symbols involve the identity of the nucleus, or particles and radiation involved.
Example: Mass
131
53 I – Iodine 131
Charge
1. Alpha Decay –alpha particles are slow moving and can be stopped by a piece of paper.
Example: Radium – 226
Summary:
2. Beta – An electron emitted at very high energy from the nucleus. Can pass through
paper but are stopped by metal foil. Produced when a neutron becomes a proton. Thus
the charge of the nucleus is increased by one proton.
How does the nucleus emit an e-
Example: Iodine 131
Summary:
3. Gamma Rays – These are related to x-rays and light. They have no mass or charge nor
does its emission change the identity of the element. They are high energy and pass
easily through matter up to several cm of lead or meters of concrete.

4. Positron - A positive electron is emitted that signifies a proton has been changed into
a neutron. Therefore the atomic # is decreased but the mass remains the same.
Ex. Potassium 37
Radioactive decay series – A series of nuclear reactions that begins with an unstable
nucleus and results with the formation of a stable nucleus. Use Table N
Half-life – The time required for half of a radioactive isotope to
decay to its product. No matter what temperature or pressure or what size the sample in
one half-life 50% of it will always decay.
% Isotope
Solving Half-life questions:
Initial amount
Fraction remaining
½ life
Half - Life

Causing nuclear reactions:
Natural Transmutation – Definition – The conversion of an atom of one element to an
atom of another element. (Natural Decay)
Artificial transmutation – The use of high energy particles to create nuclear changes and
new elements. No element higher than 92 exists naturally and are all artificially man made.
The use of nuclear accelerators to boost the kinetic energy of particles so they will cause
greater nuclear changes revolutionized the development of new isotopes.
Ex.
Nuclear fission – The break down of large unstable nuclei such as U – 235 to smaller nuclei
produces large amounts of nuclear energy. Many 1000s times more that chemical energy
cells of equal mass. The reaction is initiated by a neutron splitting U-235 into smaller stable
nuclei but also producing more neutrons. If they hit more U-235 atoms the reaction
intensifies and can go out of control. A very specific concentration of mass of U-235 must
be present to control the reaction called the critical mass.
Nuclear Fusion – The combining of smaller nuclei to form a larger more stable nuclei is
called fusion. Occurs on the sun.

Albert Einstein:
Theory of relativity: converting small amounts of mass to large amounts of energy
Glenn Seaborg:
Fusion Fission
Uses of Radioactive Substances:
Radioisotopes – Radioactive compounds that can be traced within living organisms for
medical evaluation or diseases control.
C-14 and C-12 ratio is particularly useful if tracing the chemical pathways in living plants
since the isotopes go the same way regular atoms go.
I – 131 for thyroid disorders
U-238 decay to Pb-206 for dating geological formations
Tc-99 for brain disorders
Co-60 for treating cancer

Radiotherapy and Radiotracers – Isotopes may be used in the diagnosis and treatment of
many diseases. It can also be used in larger doses to destroy cancer cells (Co and Ra).
Radiochemical Dating – The use of the half-life of an isotope such as C-14 to determine the
age of an artifact. C-14 is used to date recent organic remains because it has a half-life of
5730 y. U-238 is used to date the age of the earth because its half-life is 4.5 billion y.
Irradiation of foods
Radiation may be a boon to man in some ways but it is a curse in others. Disposal of waste
from reactors is a huge problem since the material will be radioactive for thousands of years.
Exposure to even low amounts of radiation over time can produce increased risk of cancer
and disease.
Industrial Measurement
Risks of Radiation:
Nuclear Reactors:
Standard reaction is:
Advantanges Disadvantages

Nuclear Reactors
Types -
Parts