N AM E _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ P R D _ _ _ _ _ D AT E _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ WHAT IS NUCLEAR FUSION (AND WHAT MAKES THE SUN SHINE?) Every day, you enjoy the effects of nuclear fusion, probably without even realizing it. What is nuclear fusion? Well, before I explain that, let’s take a quick refresher course in atomic theory. Everything in the universe is made up of atoms. Inside atoms there’s a nucleus, positively-charged protons, and negativelycharged electrons. Amazingly, it’s the fusion of these smaller-than-microscopic atoms that powers our sun and provides both heat and light to earth. Here’s how it works: Nuclear fusion is a reaction where two atomic nuclei fuse together to create a larger nucleus. There are various kinds of nuclear fusion, determined by what kind of atom starts the process and what kind of atom finishes the process. Our Sun uses proton-proton fusion. It begins with hydrogen atoms and ends with helium-4. This process involves several steps. First, two protons fuse to form a deuterium, among other things. Then a proton and a deuterium fuse and form helium-3. Then two helium-3 atoms form helium-4. This process releases a tremendous amount of energy. That energy is released in the form of electromagnetic radiation, and is important for us, because it provides light, and heat to Earth. Our sun fuses, on average, about 716 million tons of hydrogen each second! You need a tremendous amount of heat and pressure for nuclear fusion to occur. Stars, including our sun, have both. The amount of pressure in a star heats it up to sufficient temperatures for this process to unfold. And this process is so powerful we can feel the heat of the sun from 93 million miles away and can see stars that are many, many light years away. What about nuclear fission? Well, fusion and fission are different, and FISSION can produce some pretty deadly effects here on earth when utilized in certain ways! Yep, that kind of way! Nuclear fusion is the process we’ve covered today. Fission is the opposite process as things break down and you “split the atom”. Stars can’t continue nuclear fusion forever. Eventually they’ll run out of energy. But, that day won’t come for at least 5 billion years for OUR Sun. Everyone is now probably thinking…What about nuclear power plants and nuclear bombs that were used in war? Is that FUSION or FISSION? Remember, FUSION is a reaction where two atomic nuclei fuse together to create a larger nucleus and in the process release energy. FISSION is the process in which a large nucleus splits into two smaller nuclei with the release of energy. There are two main types of nuclear weapons: atomic bombs, which are powered by fission reactions similar to those in nuclear reactors [power plants], and hydrogen bombs, which derive their explosive power from fusion reactions. An atomic bomb slams together two pieces of fissionable material, usually uranium-235 or plutonium-239. This releases its energy instantaneously as atoms inside it split in an uncontrolled chain reaction. On August 6, 1945, an atomic bomb called Little Boy was dropped on the Japanese city of Hiroshima, followed three days later by another, called Fat Man, on Nagasaki. Hydrogen bombs fuse together hydrogen atoms to form heavier helium atoms, releasing far more energy than a fission bomb. Two isotopes of hydrogen are used – deuterium (𝐻𝐻 1 2 ) and tritium (𝐻𝐻 1 3 ). Hydrogen bombs have never been used in war and are thousands of times more powerful than atomic bombs. For questions 1-7 identify each as a fusion or fission (You may use google search) 1. Used in nuclear power plants: 2. Occurs on the sun: 3. More power per gram: 4. A larger nucleus divides to make a smaller nucleus: 5. Two hydrogen atoms fuse to make a helium atom: 6. An atomic bomb: 7. A hydrogen bomb: 8. Why can’t we use fusion reaction in a nuclear power plant? 9. Why is it so hard to dispose of nuclear waste? 10. What are the benefits to having a nuclear power plant nearby? 11. What are the hazards to having a nuclear power plant nearby? Fill in the blanks. 12. There are two types of nuclear reactions, fusion and fission. ______________ involves fusing particles together. This is the nuclear reaction that occurs in the sun. Fission involves _______________ a heavy nucleus into smaller particles. This is the reaction that produces nuclear energy. 13. Compare and contrast FISSION and FUSION in terms of energy production, particles involved and examples.