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
•Fusion reactions release more energy than fission reactions
•Sun is powered by fusion
euterium
ritium
Question Time
• What is fission?• 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•When breaking apart a
nucleus, there is a change in mass called the mass defect.
•The change in mass was converted to energy.
•We know this as E=mc2
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
Hydrogen Bomb• Uses fusion• 1000 time more powerful
than atomic bomb• Uses deuterium 2H and
tritium 3H
Sources• 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