1. Radiation Radiation

2. Radiation (Nuclear Decay) First used by Marie Curie (1899-1903) Radiation: Energy released in the form of particle or electromagnetic waves.  Measured units: rems/millirems

3. Wilhem Conrad Roentgen Robert Oppenheimer 1903 Radiation 1942 First Chain Reaction 1895 X-rays Marie Curie Enrico Fermi 1 1945 Nuclear Bomb

4. Radiation is all around Us!! Types of Radiations:  Background Radiation/ Natural Sources: A. Radon gas from rocks and soil (Decay of Uranium) B. Gamma Rays from ground C. Carbon and Potassium in the body D. Cosmic Rays at ground levels. (High energy particles from outside the Solar system) E. Building materials such as bricks, wood, and stone. ** Radiation increases as altitudes increases.

6.  Man-made Radiation Sources: A. Medical uses (X-rays, CAT and PET scans and Nuclear energy ) B. Chernobyl (First year) Japan fallout C. Fallout from weapons testing D. Job (Average) E. Nuclear Industry (Waste) F. Others (TV, airplane trips, smoke detectors)

10. Electromagnetic Spectrum Non-ionizing vs Ionizing Radiation

11. Particles Smaller particles store more energy. They have a greater impact in the body

12. Dose Response on Tissues Examples of tissue Sensitivity Very High White blood cells (bone marrow) Intestinal epithelium Reproductive cells High Optic lens epithelium Esophageal epithelium Mucous membranes Medium Brain – Glial cells Lung, kidney, liver, thyroid, pancreatic epithelium Low Mature red blood cells Muscle cells Mature bone and cartilage

13. Effects of Radiation

14. Even though we have learned about some harmful effects of radiation, have in mind the following ……..  Americans get about 25 mrems of radiation from food and water we eat each year. This number varies depending what is eaten, where it is grown and how much is eaten. (Bannanas and Brazil nuts contain higher proportions than most food)  Additional amounts of radiation come from man made sources (Mainly medical, dental, construction, and nuclear industry sources)  Americans average between 150-200 mrems of radiation from all sources each year. Places in India and Brazil may have 3,000 mrems yearly. (Radiation levels of 50,000 mrems have not produced any evident ill effects)  Strict safety standards on radiation exposure allow people to work in science, medicine, construction and nuclear power plants.

15. Activity # 2 **Answer Review Exercise **Total Annual Millirems (mrems) Dose Worksheet. Keep in mind the following facts: 1. Question #2: Monterrey’s Elevation is 537m /1,762 ft 2. Question #7: Research miles traveled per year. Example: Mty-Cancun (Round Trip) = 1900miles 3. Research has shown that 50,000 mrems have not produced any evident ill effects

16. Nuclear Stability Nucleus contain Protons and Neutrons. Contains a strong Electromagnetic force to hold the Protons together. Nucleus of some elements become unstable releasing energy as the form of radiation.

17. Radiation can be detected if it: Alters a photographic film Produces an electric charge in the surrounding air Can produce fluorescence (glowing)

18. Isotopes Atoms of an element with the same number of protons and a different number of neutrons. Therefore their mass number is also different.

20. Other Isotopes

21. Analyzing Isotopes Write the nuclear symbol for atoms with the following subatomic particles: A. 8p, 8n, 8e = B. 17p, 20n, 17e = C. 47p, 60n, 47e = Complete the following table :

22. Analyzing Isotopes Solutions Complete the following table : Protons141414 Neutrons141516 Electrons141414 Atomic #141414 Mass #282930 Write the nuclear symbol for atoms with the following subatomic particles: 16 37 A. A. 8p, 8n, 8e = O B. 17p,20n, 47e = Cl 8 17 C.47p, 60n, 47e = 107 Ag 47

23. Copper has two isotopes: Cu-63 and Cu-65. Given that the atomic mass of copper from the periodic table is 63.546 amu, which of the two isotopes is most abundant? Explain your answer. Analyze the following chart and determine what elements are isotopes of the same element. Atom AAtom BAtom CAtom D #P151015 #N1510 15 #E15 10 Mass

24. Solutions Copper has two isotopes: Cu-63 and Cu-65. Given that the atomic mass of copper from the periodic table is 63.546 amu, which of the two isotopes is most abundant? Explain your answer. The most abundant isotope is Cu-63 because it is closest to the mass of copper on the periodic table. Analyze the following chart and determine what elements are isotopes of the same element. Atom AAtom BAtom CAtom D #P151015 #N1510 15 #E15 10 Mass30202530

25. Average Atomic Mass Check this out!!! http://www.youtube.com/watch?v=xirPkC I1sMA&feature=related

26. 26 Calculating Atomic Mass Isotope Mass Abundance 24 Mg = 23.99 amu x 78.70/100 = 18.88 amu 25 Mg = 24.99 amu x 10.13/100 = 2.531 amu 26 Mg = 25.98 amu x 11.17/100 = 2.902 amu Atomic mass (average mass) Mg = 24.31 amu Mg 24.31 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

27. 27 Gallium is an element found in lasers used in compact disc players. In a sample of gallium, there is 60.11% of 69 Ga (atomic mass 68.93) atoms and 39.89% of 71 Ga (atomic mass 70.92) atoms. What is the atomic mass of gallium? Practice Activity Basic Chemistry Copyright © 2011 Pearson Education, Inc.

28. 28 69 Ga 68.93 amu x 60.11 = 41.43 amu (from 69 Ga) 100 71 Ga 70.92 amu x 39.89 = 28.29 amu (from 71 Ga) 100 Atomic mass Ga = 69.72 amu Solution 31 Ga 69.72 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

29. Radioactive Decay =

30. Half-Life Half-life: Time it takes for an isotope to decay to its half amount.

31. Decay Curve

32. Drawing a Half-life Bar Graph Draw a bar graph representing the decay of Barium-139 if you start with a 20 g sample and it must decay to less than 2 g. The half-life of Barium-139 is 80 minutes. Bar Graph Representation and Percent Fraction Remaining Mass Mass in Grams Time passed (years) # of Half-life

33. Drawing a Half-life Bar Graph Solutions Bar Graph Representation and Percent Fraction Remaining Mass Mass in Grams Time passed (years, min) # of Half-life 12.5% 100% 50% 25%

34. Drawing a Half-life Bar Graph Solutions Bar Graph Representation and Percent Fraction Remaining Mass 2/2 1/2 1/4 1/8 1/16 Mass in Grams Time passed (years, min) # of Half-life 12.5% 100% 50% 25%

35. Drawing a Half-life Bar Graph Solutions Bar Graph Representation and Percent Fraction Remaining Mass 2/2 1/2 1/4 1/8 1/16 Mass in Grams 20 g 10 g 5 g 2.5 g 1.25 g Time passed (years, min) # of Half-life 12.5% 100% 50% 25%

36. Drawing a Half-life Bar Graph Solutions Bar Graph Representation and Percent Fraction Remaining Mass 2/2 1/2 1/4 1/8 1/16 Mass in Grams 20 g 10 g 5 g 2.5 g 1.25 g Time passed (years, min) 0 min 80 min 160 min 240 min 320 min # of Half-life 12.5% 100% 50% 25%

37. Drawing a Half-life Bar Graph Solutions Bar Graph Representation and Percent Fraction Remaining Mass 2/2 1/2 1/4 1/8 1/16 Mass in Grams 20 g 10 g 5 g 2.5 g 1.25 g Time passed (years, min) 0 min 80 min 160 min 240 min 320 min # of Half-life 0 1 2 3 4 12.5% 100% 50% 25%

38. Harnessing the Nucleus Nuclear Fission Nuclear Fusion *Chain reaction *High temperatures/Sun & Star *Huge amounts of energy produced *Greater energy produced *Nuclear power plants *Less radioactive waste formed *Impossible to create artificially

39. Final Reflection on Radiation…… * *