Fission and Fusion : Fission and Fusion
Fission : Fission Mass of a nucleus is slightly less than the mass of its parts.
mnucleus < mprotons + mneutrons
mass defect
Mass defect is converted to energy, and holds the nucleus together
E = mc2
Fission Reactions : Fission Reactions Large nucleus split into two or more smaller ones, with some particles left over (maybe)
A tiny bit of mass is converted into energy
E = mc2
Law of Conservation of Matter does not hold true!
Law of Conservation ofMatter and Energy : Law of Conservation ofMatter and Energy Matter and energy can be converted
Total of mass and energy is conserved
Fission Reactions : Fission Reactions Small amount of matter is lost
Large amount of energy is produced
Matter-Energy Conversion : Matter-Energy Conversion If a total of 1 gram of matter is converted to energy, how much energy would that be?
E = mc2
E = 0.001 kg x (3 x 108 m/s)2
E = 9 x 1013 J
(1/3 of the total energy produced in PA nuclear power plants in 2006)
Nuclear Power : Nuclear Power U + n ? + ? + ? + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power U + n ? + ? + ? + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power U + n Ba + ? + ? + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power U + n Ba + Kr + ? + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power U + n Ba + Kr + ? + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power U + n Ba + Kr + ? + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power U + n Ba + Kr + 3 n + Energy
Mass numbers must balance
Atomic numbers must balance
Nuclear Power : Nuclear Power In Pennsylvania, 34% of our electricity is produced using nuclear power.
In the USA, 20% of our electricity is produced using nuclear power.
Nuclear Power Plant : Nuclear Power Plant Design
Boiling Water Reactor (BWR)
Pressurized Water Reactor (PWR)
Model
Two models will be built, labeled, compared
Questions about nuclear power
Questions about atomic theory
Nuclear Study so far… : Nuclear Study so far… Radioactive decay
Nuclear bombardment
Fission reactions
Next…
Fusion reactions
Nuclear Fusion : Nuclear Fusion Two small nuclei joined by bombardment
High temperature
High pressure
Nuclear Fusion : Nuclear Fusion H + H ? + n + Energy
Nuclear Fusion : Nuclear Fusion H + H ? + n + Energy
Nuclear Fusion : Nuclear Fusion H + H ? + n + Energy
Nuclear Fusion : Nuclear Fusion H + H He + n + Energy
Nuclear Fusion in Stars : Nuclear Fusion in Stars H He + Energy +2 e+ + 2 neutrinos
Since our sun is a smaller star, it will fuse H to He to C
Larger stars fuse C to O to Ne to Mg to Si to Fe
Nuclear Fusion in Stars : Nuclear Fusion in Stars H He + Energy +2 e+ + 2 neutrinos
Elements heavier than Fe are formed when large stars undergo supernova explosions.
Nuclear Fusion on Earth : Nuclear Fusion on Earth Because of the very high temperatures and pressures needed and the very large amount of energy released, we cannot yet control fusion reactions.