Download Fission and Fusion of Atomic Nuclei

Fission and Fusion
of Atomic Nuclei
I. Nuclear Fission
• Fission - The splitting
of the nucleus into
fragments (division)
• Uranium-235 is struck
by a neutron and
forms Ba-141, Kr-92 ,
and additional
neutrons.
Neutron
II. Chain Reaction
• Chain reaction
– Nucleus captures a
neutron and splits into
fragments and produces
three neutrons
– Products start a new
reaction
• Critical mass
– The minimum mass
required to support a
self-sustaining chain reaction
III. Nuclear Fusion
• Fusion - combining atomic nuclei to
produce a nucleus of greater mass
• the nuclei of lighter elements (such as
hydrogen) are fused together
at extremely high temperatures and
pressures to form heavier elements
(such as helium)
• Fusion reactions release more energy
than fission reactions
• Requires extremely high energies to
initiate and sustain
• Sun is powered by fusion
euterium
ritium
Question Time
• What is fission?
• What products are formed in the fission of
uranium?
• What is a chain reaction?
• What is critical mass?
• What is fusion?
• Where do we find fusion?
IV. Nuclear Binding Energy
• The energy required to break a nucleus into its
individual protons and neutrons
• Energy released in a nuclear reaction is much
greater than in chemical reactions
V. Mass Defect
• The mass of the nucleus is always less than
the sum of the masses of individual
protons and neutrons.
• Mass defect -The difference in mass
between a nucleus and its component
protons and neutrons
• The difference in mass has been converted
to energy
• The energy can be calculated using E=mc2
Question Time
• What is the nuclear binding energy?
• Which releases much more energy nuclear or
chemical reactions?
• What is the mass defect?
• What equation can be used to calculate the
mass defect?
VI. Nuclear Reactors
• The purpose of nuclear reactors is to keep the
chain reaction going without letting it get out
of control
Diablo Canyon
San Onofre
Fukushima, Japan
VII. Nuclear Bombs
Atomic Bomb
• Uses fission
• Uses enriched uranium-235
or plutonium
• Nagasaki and Hiroshima
• May 1945 trial run to Trinity
(the first atomic bomb
tested-plutonium) in New
Mexico
Hydrogen Bomb
• Uses fission and fusion
• 1000 time more powerful
than atomic bomb
• Uses deuterium 2H and
tritium 3H
• October 30, 1961, Tsar
Bomba in Novaya Zemlya
used Lithium for its bomb
Question Time
• What is the purpose of nuclear reactors?
• Which is more powerful, an atomic or
hydrogen bomb?
Sources
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www.pennenergy.com
http://www.californiareport.org
noyonews.net
www.sfgate.com
enformable.com
www.utsandiego.com
activerain.com
thesportdigest.com
www.dailytelegraph.com.au
www.2050publications.com