2 - 1 CH 104 Chapter 3: Nuclear Chemistry Radioactivity Nuclear Equations Radiation Detection Half-Life Medical Applications Fission & Fusion

2 - 2 CH 104 Isotopes of Hydrogen Isotopes = Isotopes = Atoms of the same element but having different masses H H H Protium99.99% Deuterium0.01% Tritium Trace % Average Atomic weight Average Atomic weight of Hydrogen amu = amu

2 - 3 CH 104 Isotopes of Carbon Average Atomic weight amu Average Atomic weight of C= amu 98.89% C 612C 613 C % Trace %

2 - 4 CH 104 Radioactive Isotopes C H - Nucleus is unstable So falls apart (decays) Giving radioactive particles Hydrogen-3 Carbon-14

2 - 5 CH 104 Radioactive Isotopes in Medicine Tc 4399m I 131 I 6027 Co Diagnose thyroid function Treat hyperthyroid (destroys cells) Destroy tumors (  radiation) Diagnose bone, tissue (most common)

2 - 6 CH 104 Alpha Decay Pb Po 42 He ++  Particle Po Pb He

2 - 7 CH 104 Beta Decay N C 0 e -  Particle n 11 H + 0 e neutronprotonelectron

2 - 8 CH 104 Beta Decay N C 0 e -  Particle e 146 C N 7 14

2 - 9 CH 104 Gamma Decay 99m43 Tc  decay Tc + 99m43 Tc Tc 

CH 104 Radiation: Penetration through Air ++ -  cm cm 500 m

CH 104 Radiation: Shielding ++ -  Paper Cloth Heavy Cloth Pb, thick concrete

CH -  Tissue Penetration Depth 0.05 mm 4-5 mm 4-5 mm >50 cm

CH 104 Nuclear Equations Ra Rn He  Radon gas in Buildings Po He

CH I Xe e  Thyroid check & treatment  Cancer Treatment Nuclear Equations 6027 Co Ni e

CH 104 Radiation Detection 1 Ci = 3.7 x disintegrations sec 1 Bq = 1 disintegration sec # of disintegrations by of 1g Ra ActivityActivity Becquerel (Bq) Curie (Ci) Curie (Ci):

CH 104 Radiation Detection Absorbed Dose

CH 104 Radiation Detection ++-   0.05 mm 4-5 mm 4-5 mm >50 cm Tissue Penetration Depth Absorbed Dose

CH -  0.05 mm 4-5 mm 4-5 mm >50 cm Radiation Absorbed Dose (Rad) (D) Radiation Absorbed Dose (Rad) (D): 1 rad = 1 x J 1 kg tissue 1 kg tissue 1 rad = 1 x J 1 kg tissue 1 kg tissue 1 rad = 2.4 x cal 1 kg tissue 1 kg tissue 100 rad = 1 Gray (Gy)

CH 104 Radiation Detection Biological Damage

CH 104 Radiation Equivalent for Man (rem)    1 remRBE 1 rem = 1 rad x RBE RBE2011RBE2011 Damage (rem) = absorbed dose (rad) X factor (relative biological effectiveness) 100 rem 100 rem = 1 sievert (Sv)

CH 104 Annual Radiation Exposure in USA Ground = 15 mrem Air, H 2 O, Food = 30 mrem Cosmic = 40 mrem Wood,concrete,bricks = 50 mrem X-rays: Chest = 50 mrem Dental = 20 Smoking = 35 mrem TV = 2 mrem Radon = 200 mrem

CH 104 Biological Effects of Radiation Dose in rem 0-25genetic damage possible but usually undetected decrease # of white blood cells (temporary) mild radiation sickness (vomit, diarrhea, strong decrease # white blood cells) >300 (diarrhea, hair loss, infection) 500LD 50 for humans Dose in rem 0-25genetic damage possible but usually undetected decrease # of white blood cells (temporary) mild radiation sickness (vomit, diarrhea, strong decrease # white blood cells) >300 (diarrhea, hair loss, infection) 500LD 50 for humans

CH LD 50 for dogs 500LD 50 for humans 800 LD 50 for rats 50,000 LD 50 for Bacterium 100,000 LD 50 for Insects Biological Effects of Radiation Dose in rem

CH 104 Half-Life t 1/2 = Time for 1/2 sample to decay m = g(0.5) t I 20 g t 1/2 = 8 days 10 g 8 days 5 g Mass remaining Beginning mass # of half lifes

CH 104

CH 104 t m = g(0.5) t I 20. g t 1/2 = 8 days 10. g 8 days 5.0 g How much I-131 will be left after 72 days? Half-Life = 20. g(0.5) 9 72 days 1 1 half-life = 8 days 9 9 half-lifes =.039 g

CH 104 Positron Emission Tomography PET

CH 104 Fission U 1010 n U Kr Ba unstable Splitting atoms for Energy

CH 104 Fission Need critical mass of U-235

CH He Fusion 2121 H 3131 H + + Deuterium Tritium n Combining atoms for Energy

CH 104 Fusion

CH 104

CH 104