Guided Reading - Nuclear Chemistry
Energy is a hot debate topic these days. Many
people want to switch from using fossil fuels such
as oil and natural gas to other energy sources that do not
release carbon dioxide into the atmosphere. They are
concerned about the effects of carbon dioxide on climate
change.
This concern has prompted interest in increasing
the number of nuclear power plants. Nuclear power plants do
not produce carbon dioxide, but their operation is associated
with many risks. That
puts society in a bind—should nuclear power be
used as a source of energy or not?
White clouds of steam are released from
the cooling towers of an operating nuclear
power plant.
Question 1: What is one advantage in using power plants in comparison to burning fossil fuels?
Nuclear Reactions: Changes in the Nucleus of an Atom
When we think about chemistry, we tend to focus on changes that occur as electrons are traded or
shared between atoms during chemical reactions. During these changes, the nuclei of atoms do not
participate—only electrons are involved as one set of chemical bonds is broken and a new set of
bonds is formed.
However, another category of reaction involves changes in atomic nuclei. As such, they are called
nuclear reactions. Nuclear chemistry is the branch of chemistry that deals with the properties and
reactions of atomic nuclei.
Question 2: How do nuclear reactions differ from chemical reactions?
Fission and Fusion
Some nuclear reactions involve nuclear decay and other
nuclear reactions involve the bombardment of a nucleus with
other particles.
Note: Types of nuclear decay (alpha, beta, and gamma) is part of
chemistry TEKS and won’t be discussed in IPC course.
• Fission: Fission is a nuclear reaction that occurs when a
large nucleus collides with a small particle, neutron. The large
nucleus splits into two or more smaller nuclei, releasing a large
amount of energy. (In fact, the term fission comes from a Latin
word meaning
“to split.”) An example of a fission reaction is shown in
the illustration at right.
During nuclear fission, a large nucleus
splits into smaller nuclei.
Question 3: What does the word “fission” mean? _____ What is fission?
Question 4: Fission reaction releases a large amount of ______.
Nuclear power plants are powered by fission reactions. The typical fuel is uranium-235,
which undergoes a fission reaction when it is bombarded with neutrons.
Question 4: What particle is used to split an atom of uranium? Label this particle in the picture above.
Guided Reading - Nuclear Chemistry
• Fusion: Fusion occurs when two small nuclei collide
and combine to form one larger nucleus. The word
“fusion” means “to combine.” An example of a fusion
reaction is shown in the illustration at right.
Question 5: What does the word “fusion” mean?
What is fusion?
This example shows the fusion of a deuterium nucleus with a
tritium nucleus. Deuterium (
) and tritium (
) are both
isotopes of hydrogen. (As you see in the illustration, each isotope
has one proton; however, deuterium has one neutron and tritium
has two neutrons.) Along with the change in nuclear makeup,
large amounts of energy are released during fusion. In fact,
the energy released by stars, including the Sun, comes from
nuclear fusion inside the star’s core.
Nuclear fusion involves two small
nuclei fusing to form one larger
nucleus.
Question 6: How do nuclei of deuterium and tritium different?
Fusion releases a large amount of _____
Looking to the Future: Fusion as an Energy Source
Right now, nuclear power plants have been engineered to run on fission reactions only. While nuclear
fission produces a great deal of energy, the hazards associated with maintaining fission-based
nuclear power plants have many people concerned. Fissionable fuel is highly radioactive. The waste
products of the fission process are also highly radioactive. These materials must be contained and
kept shielded from humans. Normally, this can be accomplished. However, natural or manmade
disasters could compromise any containment of these
materials. This makes running a nuclear power plant difficult
and potentially hazardous.
Question 7: Nuclear power plants are powered by _____
reactions.
Question 8: What are the concerns regarding running a
nuclear power plant?
That is why scientists are exploring the possibility of
developing power plants that can run on nuclear fusion
reactions. Fusion reactions are associated with far fewer
hazards than fission reactions. The wastes are safe - not
radioactive. Fusion produces “Clean Energy”. Switching from
fission to fusion would improve the safety of nuclear power
generation.
Question 8: Why is fusion a better alternative to generating
electricity than fission?
Scientists involved in the National
Spherical Torus Experiment at Princeton
University are experimenting with
ways to harness nuclear fusion as a
source of power.
(Photo courtesy of the U.S.
Department of Energy)
Many projects are underway all over the world to build a fusion reactor. Success is still far away
because the prototypes built so far need more energy to initiate the fusion process than the process
itself generates. The aim is to design a reactor that will be more self-sustaining so that it has a net
generation of energy.
Question 8: What is the main obstacle in building a fusion reactor to generate “clean” energy?