FISSION AND FUSION Unit 7 C

FISSION The process where a nucleus splits into two or more smaller fragments, releasing neutrons and energy The process where a nucleus splits into two or more smaller fragments, releasing neutrons and energy SPLIT! SPLIT! Can be seen in nuclear power plants and atomic bombs Can be seen in nuclear power plants and atomic bombs

SIMPLE DIAGRAM OF FISSION

Neutrons are used as bullets to break apart the uranium nucleus. Neutrons are used as bullets to break apart the uranium nucleus. Barium and Krypton result from this fission. Barium and Krypton result from this fission. Energy is released as well as three free neutrons. Energy is released as well as three free neutrons.

Energy Released in Fission Fission reactions release tremendous amounts of energy Fission reactions release tremendous amounts of energy Energy released in 1 fission reaction = amount of energy of 6.7 million TNT molecules when they explode! Energy released in 1 fission reaction = amount of energy of 6.7 million TNT molecules when they explode!

Chain Reactions A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. This nucleus in turn produces neutrons, and the process repeats. The process may be controlled (nuclear power) or uncontrolled (nuclear weapons). The process may be controlled (nuclear power) or uncontrolled (nuclear weapons).

Chain Reactions

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FUSION The opposite of a fission reaction. The opposite of a fission reaction. Two or more lighter nuclei combine to form a heavier nucleus. Two or more lighter nuclei combine to form a heavier nucleus. FUSE! (Come together) FUSE! (Come together) Takes place in the sun and stars Takes place in the sun and stars

ENERGY IN FUSION Scientist must create super high temperatures so that the isotopes can be hurled at each other and overcome the tendency of positively charged nuclei to repel each other. Scientist must create super high temperatures so that the isotopes can be hurled at each other and overcome the tendency of positively charged nuclei to repel each other.

Diagram of Fusion

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Nuclear Medicines POSITIVE: Use radiation to kill cancer cells Use radiation to kill cancer cells Check body systems to make sure working properly Check body systems to make sure working properlyNEGATIVE: Nuclear waste Nuclear waste Healthy tissue is damaged Healthy tissue is damaged

Nuclear Weapons Tremendous amounts of energy available from small amounts of fuel so it can be “smuggled easily.” Tremendous amounts of energy available from small amounts of fuel so it can be “smuggled easily.” Tremendous amount of destruction, both material and biological. Tremendous amount of destruction, both material and biological. Contamination of the environment with fission-product isotopes, many of which are radioactive and remain so for very long periods of time. Contamination of the environment with fission-product isotopes, many of which are radioactive and remain so for very long periods of time.

Nuclear Energy BENEFITS Tremendous amounts of energy available from small amounts of fuel Tremendous amounts of energy available from small amounts of fuel No air pollution from the burning of fossil fuels, No air pollution from the burning of fossil fuels, Can be used anywhere (as opposed to wind power, solar power, hydroelectric power, etc) Can be used anywhere (as opposed to wind power, solar power, hydroelectric power, etc) Abundance of fuel Abundance of fuel Non-reliance on fossil fuel Non-reliance on fossil fuel

NUCLEAR ENERGY NEGATIVES: Can cause thermal pollution to water systems Can cause thermal pollution to water systems Waste from nuclear fission reactors must be stored in a special way until it is no longer radioactive, which can be a very long time. Waste from nuclear fission reactors must be stored in a special way until it is no longer radioactive, which can be a very long time. Improper handling of nuclear materials and possible leaks can cause radioactive isotopes to contaminate the environment, causing long-term radioactive decay problems. Improper handling of nuclear materials and possible leaks can cause radioactive isotopes to contaminate the environment, causing long-term radioactive decay problems. Power plant failure – radioactive explosions Power plant failure – radioactive explosions