Nuclear Reactions
Review- Physical Changes What is a physical change? Chemical composition of the substances does not change
Review- Chemical Changes What is a chemical change? Different substances are formed
Law of Conservation of Energy Conservation means to: save or preserve Energy cannot disappear or appear from nothing Closed system: An isolated system with no interaction with the surrounding environment
Law of Conservation of Energy Energy cannot be created or destroyed but only changed from one form to another What does this mean? No matter how substances within a closed system are changed, the total mass remains the same Closed system: An isolated system with no interaction with the surrounding environment
Nuclear Reactions What do you know about nuclear reactions? Nuclear energy is energy stored in the nucleus of an atom Two ways to harness nuclear energy In nuclear reactions, a small amount of matter produces a large amount of energy.
Nuclear Reactions Two ways to harness nuclear energy Fusion Fission In nuclear reactions, a small amount of matter produces a large amount of energy.
Fusion Joining nuclei together Small amounts of matter are converted into energy Occurs in the Sun and other stars No radioactive waste
Fission Splitting of an atom’s nucleus Sum of new masses < original mass What happened to the missing mass? Current type of nuclear reactions used to generate electricity. Produces radioactive waste. When a nucleus fissions, it splits into several smaller fragments. These fragments, or fission products, are about equal to half the original mass. Two or three neutrons are also emitted. The sum of these masses is equal to less then the mass of the original atom. The missing mass has been converted into energy.
Chain Reaction When one fission reaction causes more fission reactions to occur
Chain Reaction
Viewpoints Foldable What is Fusion? What is Fission? Advantages of Nuclear Power Disadvantages of Nuclear Power
Pros and Cons Advantages Disadvantages Fission has low operating costs Expensive to build nuclear power plants Small amount of matter produces a large amount of energy Radioactive waste Produces no air pollution Nuclear accidents or spills possible Does not contribute to climate change Uranium fuel is nonrenewable