11 ELECTROMAGNETIC RADIATION

22 EM RADIATION II ALSO CALLED RADIANT ENERGY ONLY A PORTION IS CALLED LIGHT TRAVELS IN WAVES TRAVELS THROUGH SPACE (VACUUM)

33 WAVE PROPERTIES WAVELENGTH – DISTANCE BETWEEN PEAKS FREQUENCY – NUMBER OF PULSES PER SECOND FREQUENCY UNIT IS HERTZ (1/SECONDS)

44 WAVELENGTH & FREQUENCY INVERSELY RELATED

5 RADIATION REFERS TO RADIANT ENERGY OR HIGH ENERGY PARTICLES THAT CAN TRAVEL THROUGH SPACE SOME CALLED IONIZING RADIATION WHICH MEANS IT HAS ENOUGH ENERGY TO REMOVE ELECTRONS FROM ATOMS HIGH FREQUENCY IS IONIZING, LOW FREQUENCY IS NOT

6 IONIZING AND NON- IONIZING RADIATION

7 NON-IONIZING (LOW ENERGY) RADIATION TV AND RADIO WAVES MICROWAVES INFRARED WAVES VISIBLE LIGHT

8 IONIZING (HIGH ENERGY) RADIATION ULTRAVIOLET (UV) RAYS X-RAYS GAMMA RAYS

9 RADIATION DAMAGE THE HIGHER THE ENERGY, THE GREATER DAMAGE IT CAN CAUSE REM IS A UNIT OF RADIATION THAT AFFECTS ORGANISMS

10 SOURCES OF RADIATION EXPOSURE

11 RADIOACTIVITY A CHANGE IN THE NUCLEUS THAT PRODUCES IONIZING RADIATION THAT LEAVES THE NUCLEUS RADIOACTIVE DECAY (OR JUST DECAY) IS THE CHANGE IN THE NUCLEUS PRODUCES NUCLEI THAT ARE CLOSER TO STABLE NEUTRON-PROTON RATIOS ORIGINAL NUCLEUS IS PARENT PRODUCT NUCLEUS IS DAUGHTER

12 RADIOACTIVITY II ALL ISOTOPES WITH Z ≥ 84 AND MANY WITH Z < 84 ARE UNSTABLE (RADIOACTIVE) CALLED RADIOISOTOPES OCCUR NATURALLY CAUSES TRANSMUTATION - CHANGING IDENTITIES OF ATOMS

13 TYPES OF NUCLEAR DECAY ALPHA PARTICLE EMISSION BETA PARTICLE EMISSION GAMMA RAY EMISSION

14 CHARACTERISTICS OF RADIATION

15 PENETRATING POWER OF RADIATION ALPHA IS LEAST GAMMA IS GREATEST

16 NUCLEAR EQUATIONS SUM OF MASS NUMBERS AND ATOMIC NUMBERS ON BOTH SIDES MUST BE EQUAL PARENT GOES ON LEFT SIDE DAUGHTER ON THE RIGHT SIDE WITH ANY RADIATION GIVEN OFF

17 ALPHA PARTICLE EMISSION IS HELIUM NUCLEUS SYMBOL I S 2 4 He DECREASES A BY 4 AND Z BY 2 Z A X → Z-2 A-4 Y He

18 BETA PARTICLE EMISSION NEUTRON DECAYS INTO PROTON AND e - e - EJECTED OUT OF NUCLEUS A REMAINS CONSTANT, BUT Z INCREASES BY 1 Z A X → Z+1 A Y e Ra-228 →Ac e

19 GAMMA RAY EMISSION HIGH ENERGY NUCLEUS EMITS GAMMA RAYS, WHICH RESULTS IN LOWER ENERGY STATE GAMMA RAY EMISSION OFTEN ACCOMPANIES OTHER NUCLEAR DECAY DOES NOT CHANGE A OR Z

20 NUCLEAR EQUATION EXAMPLES WRITE A NUCLEAR EQUATION FOR THE FOLLOWING: –Pu-245 UNDERGOING ALPHA DECAY –Es-250 UNDERGOING BETA DECAY –Th-236 UNDERGOING ALPHA DECAY WITH GAMMA RAY EMISSION

21 DECAY SERIES OFTEN A SINGLE DECAY DOES NOT PRODUCE A STABLE NUCLEUS DAUGHTERS CONTINUE TO DECAY IN A SERIES UNTIL A STABLE DAUGHTER IS PRODUCED

22 EXAMPLE DECAY SERIES FOR U-238

23 Decay Series For U-238

24 NUCLEAR BOMBARDMENT BOMBARDING A NUCLEUS WITH HIGH SPEED PARTICLES TO CAUSE TRANSMUTATION TO A HEAVIER ATOM ALL ATOMS WITH Z > 92 MADE THIS WAY PARTICLES CAN BE ANY SUBATOMIC PARTICLE OR EVEN SMALL NUCLEI

25 PARTICLE SYMBOLS PROTON H NEUTRON n

26 BOMBARDMENT EXAMPLES WRITE THE NUCLEAR EQUATION TO SHOW ISOTOPE IS CREATED WHEN –Nb-96 IS BOMBARDED WITH ALPHA PARTICLES –Pu-241 IS BOMBARDED WITH PROTONS –Am-245 IS BOMBARDED WITH NEUTRONS –Rn-222 IS BOMBARDED WITH LITHIUM ATOMS

27 HALF LIFE TIME IT TAKES FOR HALF OF THE RADIOACTIVE SAMPLE TO DECAY IS PROBABILISTIC, SO NOT EXACT EACH RADIOISOTOPE HAS UNIQUE VALUE WIDE RANGE OF VALUES FOR DIFFERENT ISOTOPES

28 EXAMPLE HALF LIVES Rn-222 HALF LIFE = 3.8 DAYS

29 FRACTION REMAINING n = NUMBER OF HALF LIVES (1/2) n = FRACTION OF ORIGINAL SAMPLE REMAINING

30 FRACTION REMAINING II

31 HALF LIFE EXAMPLE THE HALF LIFE OF Pa-234 IS 6.75 HOURS WHAT FRACTION OF A SAMPLE REMAINS AFTER 54 HOURS?

32 MASS DEFECT SUM OF MASSES OF PROTONS AND NEUTRONS IS SLIGHTLY > MASS OF NUCLEUS SOME MASS CONVERTED INTO ENERGY WHEN NUCLEUS FORMS (LAW OF CONSERVATION OF MASS IS NOT OBEYED BY NUCLEAR REACTIONS) DIFFERENCE IN MASS CALLED MASS DEFECT

33 EINSTEIN’S EQUATION E = mc 2 USED TO CALCULATE THE ENERGY RELEASED WHEN MASS DESTOYED IN NUCLEAR REACTION TINY AMOUNTS OF MASS PRODUCE LARGE AMOUNTS OF ENERGY

34 BINDING ENERGY MASS DEFECT TURNS INTO ENERGY THAT HOLDS NUCLEUS TOGETHER

35 NUCLEAR FUSION COMBINING TWO NUCLEI TO FORM ONE EXTREMELY HIGH TEMPERATURES REQUIRED TO SUPPLY ENERGY NEEDED TO OVERCOME PROTON REPULSION STRUCTURAL MATERIALS CANNOT WITHSTAND SUCH HEAT, SO MAGNETIC CONFINEMENT REQUIRED 3,000,000 K ACHIEVED, BUT NOT HIGH ENOUGH TO SUSTAIN FUSION

36

37 NUCLEAR FISSION SPLITTING OF A NUCLEUS TO FORM TWO SMALLER NUCLEI USUALLY OCCURS AFTER UNSTABLE NUCLEUS ABSORBS A NEUTRON FISSION PRODUCTS VARY GREATLY – OVER 200 DIFFERENT NUCLIDES FORMED FROM U NEUTRONS ALSO PRODUCED

38 FISSION OF U-235

39 ENERGY BOTH FISSION AND FUSION RELEASE ENERGY BY CONVERSION FROM MASS FISSION RELEASES 26 MILLION TIMES MORE ENERGY THAN COMBUSTION OF METHANE THIS IS WHY IT IS A DESIREABLE ENERGY SOURCE

40 CHAIN REACTION NEUTRONS PRODUCED FROM FISSION CAN CAUSE ADDITIONAL FISSIONS NUMBER OF FISSIONS WILL GREATLY INCREASE SINCE 2-3 NEUTRONS PRODUCED PER FISSION

41 Fission Process in which each Event Produces Two Neutrons

42 CHAIN REACTION TERMS SUBCRITICAL – A FISSION REACTION PRODUCES < 1 SUBSEQUENT FISSION CRITICAL – A FISSION REACTION PRODUCES EXACTLY 1 SUBSEQUENT FISSION SUPERCRITICAL – A FISSION REACTION PRODUCES > 1 SUBSEQUENT FISSIONS

43 CRITICAL MASS QUANTITY OF FISSIONABLE MATERIAL THAT CAN HAVE SELF-SUSTAINING CHAIN REACTION MUST BE LARGE ENOUGH TO INSURE NEUTRONS REACT BEFORE ESCAPING

44 NUCLEAR WEAPONS HAVE TWO SUBCRITICAL MASSES THAT ARE FORCED TOGETHER BY A CONVENTIONAL EXPLOSION BECOMES A SUPERCRITICAL MASS LEADING TO A NUCLEAR EXPLOSION

45 NUCLEAR REACTORS DESIGNED TO OPERATE A CRITICAL CHAIN REACTION SOME NEUTRONS ABSORBED BY CONTROL RODS TO CONTROL REACTION AFTER BEING BORN IN A FISSION, NEUTRONS MUST LOSE ENERGY SO THEY CAN BE EFFICIENT IN CAUSING A FISSION

46 MODERATOR CAUSES NEUTRONS TO LOSE ENERGY WATER USED AS A MODERATOR AND A HEAT TRANSFER MEDIUM

47 Reactor Core

48 Nuclear Power Plant Diagram