1. Nuclear Fission and Fusion

2. Nuclear Reactions Nuclear reactions deal with interactions between the nuclei of atoms Both fission and fusion processes deal with matter and energy Matter and energy cannot be created nor destroyed (Law of Conservation of Energy) Matter and energy are two forms of the same thing

3. E = mc 2 Matter can be changed into Energy Einstein’s formula above tells us how change occurs In the equation: E = Energy m = Mass c = Speed of Light (Universal Constant)

4. E = mc 2 The equation may be read: Energy (E) is equal to Mass (m) multiplied by the Speed of Light (c) squared This tells us that a small amount of mass can be converted into a very large amount of energy because the speed of light (c) is an extremely large number

5. Parent and daughter elements Parent – radioactive element before nuclear decay Daughter element – new element created as a result of nuclear decay Half-life – time needed for ½ of parent element to change into daughter product

6. Nuclear Fission Fission is Exothermic (gives off heat) The sum of the masses of the resulting nuclei is less than the original mass (about 0.1% less) The “missing mass” is converted to energy according to E=mc 2

7. Fission Nuclei of heavy atoms are struck by neutrons, initiating the fission process Nuclear fission: A large nucleus splits into several small nuclei when impacted by a neutron; energy is released in this process

9. Nuclear Fusion and the Sun Proton-proton chain reaction Hydrogen nuclei (protons) fuse together to create a helium isotope Helium isotopes fuse to make beryllium which breaks down Two protons are released and it starts again. Nuclear fusion: Several small nuclei fuse together and release energy.

10. Nuclear Fusion In nuclear fusion, two nuclei with low mass numbers combine to produce a single nucleus with a higher mass number. H 2 1 + He 4 2 + n 1 0 H 3 1 + Energy

11. Nuclear Fusion DEUTERIUM TRITIUM HELIUM NEUTRON

12. Nuclear Fusion H HeHe 1kg Hydrogen.993 kg Helium

13. Nuclear Energy for good or ill

14. Uses for radioactive isotopes Radiocarbon dating

15. Uses for radioactive isotopes Establishing age of earth and solar system

16. Uses for radioactive isotopes Plate tectonics

17. Uses for radioactive isotopes Medical diagnostics and treatment

18. Uses for radioactive isotopes Energy

19. References www.southerncompany.com/learningpower/pdf/Introduction%20to%20Fis sion%20and%20Fusion.ppt www.southerncompany.com/learningpower/pdf/Introduction%20to%20Fis sion%20and%20Fusion.ppt www.worldofteaching.com/powerpoints/physics/Fission%20and%20Fusio n.ppt www.worldofteaching.com/powerpoints/physics/Fission%20and%20Fusio n.ppt education.jlab.org/jsat/powerpoint/fusion_and_fission.ppt nuclear.inl.gov/teachers-workshop/2007/d/danel_fission_and_fusion.ppt courses.washington.edu/twsteach/ESS/302/302433%20PP/ESS302NumDat ingpt1.ppt www.genestn.org/ppts/GENES-1.PPT www.genestn.org/ppts/GENES-1.PPT www.lsa.umich.edu/UMICH/physics/Home/Seminars%20and%20Colloquia /Saturday%20Morning%20Physics/.../311.ppt www.lsa.umich.edu/UMICH/physics/Home/Seminars%20and%20Colloquia /Saturday%20Morning%20Physics/.../311.ppt www.worldofteaching.com/powerpoints/physics/Radioactive%20Decay.p pt www.worldofteaching.com/powerpoints/physics/Radioactive%20Decay.p pt en.wikipedia.org/wiki/nuclear

20. A review of atomic structure  - - - - - - - -        Negative electrons Positive protons Neutral neutrons Nucleus

21. Alpha decay: the nucleus of the radioactive isotope emits and alpha (  ) particle, comprising of 2 Alpha Decay: neutrons and 2 protons. The atomic number of the isotope decreases by 2, while the mass number decreases by 4. 234 U decays to 230 Th by alpha decay.

22. Beta Emission (Decay): a neutron emits a beta (  ) particle (similar to an electron) and is transformed into a proton. The atomic number of the atom has increased by one while the mass number remains unchanged. The decay of 14 C to 14 N occurs via  emission.

23. The Fusion Process H 2 1 H 3 1

24. H 2 1 H 3 1

25. H 2 1 H 3 1

29. He 4 2 n 1 0 ENERGY

30. The Fusion Process He 4 2 n 1 0 ENERGY

31. A Chain Reaction caused by Fission

32. U 235 92 n 1 0 The Fission Process A neutron travels at high speed towards a uranium-235 nucleus.

33. U 235 92 n 1 0 The Fission Process A neutron travels at high speed towards a uranium-235 nucleus.

34. U 235 92 n 1 0 The neutron strikes the nucleus which then captures the neutron. The Fission Process

35. U 236 92 The nucleus changes from being uranium-235 to uranium-236 as it has captured a neutron. The Fission Process

36. The uranium-236 nucleus formed is very unstable. The Fission Process It transforms into an elongated shape for a short time.

37. The uranium-236 nucleus formed is very unstable. The Fission Process It transforms into an elongated shape for a short time.

38. The uranium-236 nucleus formed is very unstable. The Fission Process It transforms into an elongated shape for a short time.

39. It then splits into 2 fission fragments and releases neutrons. The Fission Process 141 56 Ba 92 36 Kr n 1 0 n 1 0 n 1 0

40. Electron (  )- Capture: a proton captures an electron and is transformed into a neuton; emits a gamma (  ) particle. The atomic number of the atom has decreased by one while the mass number remains unchanged. The decay of 40 K to 40 Ar occurs via  capture.