Fission and Fusion of Atomic Nuclei I Nuclear

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

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 atom is always less than the sum of the masses of individual parts. • Mass defect -The difference in mass between an atom and its (protons, neutrons, and electrons) • The difference in mass has been converted to energy • The energy can be calculated using E=mc 2

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 2 H and tritium 3 H • October 30, 1961, Tsar Bomba in Novaya Zemlya used Lithium for its bomb

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. 2050 publications. com