Understanding Nuclear Radiation and Decay Phenomena

1. Nuclear RadiationGeorgia Performance Standards SPS3. Students will distinguish the characteristics and components of radioactivity. a. Differentiate among alpha and beta particles and gamma radiation. b. Differentiate between fission and fusion. c. Explain the process half-life as related to radioactive decay. d. Describe nuclear energy, its practical application as an alternative energy source, and its potential problems.

2. Nuclear Radiation • 3 Types: • Alpha Decay (Radiation) • Beta Decay (Radiation) • Gamma Radiation

3. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Radioactivity matter or energy given off by an unstable nucleus energy

4. Alpha Decay • Gives off 2 protons and 2 neutrons (like a Helium-4 atom) (alpha particle) • Weak penetration; can be stopped by a piece of paper • Can protect yourself with clothing; must swallow it to be harmful • Some alpha emitters: radium, radon, uranium, thorium • Usually from elements with high # protons

5. Alpha decay In alpha decay, the STRONG force is unable to hold the protons in the nucleus well so particles are given off to stabilize the nucleus.

6. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Alpha particles made of two protons and two neutrons 4 symbol: He 2 mass = 4 charge = +2

7. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Transmutation changing one element into another through nuclear decay 210 Po 206 Pb 4 He 2 84 82 Polonium-210 decays to lead-206 and one alpha particle

8. Alpha decay

9. Useful alpha particles smoke detector

10. Beta Decay • Gives off an electron (beta particle) • A neutron is changed to a proton • Cannot penetrate a piece of aluminum foil • Clothing provides some protection • Some beta emitters: carbon-14, strontium-90 and sulfur-35 • Usually from radioactive isotopes where # neutrons are different from # protons

11. + + + + + + + + + + + + + + e- Beta Particles • a neutron decays into a proton • one electron is emitted 131 I 131 Xe e- 0 53 54 -1

12. Beta Decay

13. Beta Decay

14. Gamma Radiation • Is a type of electromagnetic wave, not a particle • High energy electromagnetic waves • Very penetrating, need several inches of lead to stop radiation • Can penetrate human tissue and thick layers of clothing • Examples of gamma emitters: radium-226, cesium-137, uranium-235

15. Penetration of Radiation Types

16. Penetration of Radiation Types

17. Why does Nuclear Radiation occur? • The nucleus is unstable and it is giving off energy or particles to become stable • So it goes through a SERIES of radioactive decay until it becomes an element that is no longer unstable (radioactive) (like Lead!!) • Strong force the force that holds protons in the nucleus together (because they usually repel each other)

18. Decay Series

19. Radioactive Half-Life

20. List of Radioactive Half-Lives Beryllium...................2,700,000 years      Calcium.....................100,000 years      Cesium-137................30 years      Cesium-135................2,000,000 years      Rubidium...................47,000,000,000 years      Palladium...................7,000,000 years      iodine-129..................17,200,000 years      plutonium-239............24,390 years      strontium-89...............53 days      strontium-90...............28 years      tin-126.......................100,000 years      uranium-235........................713,000,000 years      uranium-238...............4,510,000,000 years Carbon-14…………..5700 years

21. Sources of Nuclear Radiation • Nuclear Fission and Nuclear Fusion give off all three types of radiation. • When mass is “lost”, energy is produced • “Lost” mass is converted to energy

22. Einstein’s Theory of Relativity • Explains energy-mass transformation: • E = mc2 • E stands for energy. • m stands for mass. • c stands for the speed of light (the speed of light is (300 million m/sec)

23. Nuclear Fission Splitting the nucleus of an atom

24. Nuclear Fusion when two nuclei combine to form one nuclei

25. Nuclear Power • Nuclear Power plants use NUCLEAR FISSION to produce electricity to power our homes/cities.

26. Controlled Chain Reactions Fuel rods contain Uranium-235 which is the fissionable material. (Above) Control rods are plunged into reactor to absorb neutrons if reactor temp gets too hot. 

27. Nuclear Power Plant Energy Conversion • _________________ energy (nucleus splits/fission) is converted to ____________ energy (causing steam) which is converted to ________________ energy (steam turns turbine) which produces ______________ energy.

28. Nuclear BombsUncontrolled Chain Reactions • Fission Bomb  Atomic Bomb (A-bomb) • Fusion Bomb  Hydrogen Bomb (H-bomb) • Fusion bomb more powerful than fission bomb, actually takes a FISSION reaction to start fusion reaction. • The U.S. has never dropped an H-bomb, they dropped an Atomic bomb on Hiroshima and Nagasaki in 1945 (WWII)

29. Bombs dropped in Japan Same picture, shows size of each better 

30. Pictures of Hiroshima and Nagasaki Hiroshima burn victim Nagasaki At ground level DURING bombing  Hiroshima after bombing

31. Pictures of Bomb Explosions H- Bomb A-Bomb

32. Radiation Detectors Cloud chamber (Wilson chamber) Bubble chamber Geiger-Muller Counter 

33. Any Questions? That is all ye need to know about radiation!! Oh, who knows? What is the name of the project that developed the first nuclear bomb? The Manhattan Project!!