CHAPTER 9 - NUCLEAR CHEMISTRY

 

9.10  NUCLEAR FUSION-ARTIFICIAL TRANSMUTATION

 

            1.  Fusion

                        98 % of all matter in the universe is hydrogen  (Big Bang!)

                                    1H  +  1 ®  2He  + on + energy

                        in the sun and in the bomb

 

            2.  Artificial Transmutation

                        All trans-uranium elements (93-112) are artificial

                        products of man-made bombardment reactions

 

 

9.11 SOME MEDICALLY USEFUL RADIOACTIVE ISOTOPES

 

                        Isotope                                                                      Use

 

1H3              Tritium (hydrogen-3)                               Measure water content of the body

6C11            Carbon-11                                              Brain scan with positron emission

                                                                                    transverse tomography (PET) to

                                                                                    trace glucose pathway

 

6C14            Carbon-14                                              Radioimmunoassay

15P32           Phosphorous-32                                     Detection of eye tumors

 

24Cr51         Chromium-51                                           Albumism diagnosis, size and

                                                                                    shape of the spleen, gastro-

                                                                                    intestinal disorders

 

26Fe59         Iron-59                                                   Bone marrow function, diagnosis

                                                                                    of anemias

27Co60         Cobalt-60                                                Treatment of cancer

31Ga67        Gallium-67                                              Whole-body scan for tumors

34Se75        Selenium-75                                           Pancreas scan

36Kr81m         Krypton-81m                                           Lung ventilation scan

 

38Sr85         Strontium-85                                           Bone scan for bone diseases,

                                                                                         including cancer

 

43Tc99m       Technetium-99m                                     Brain, liver, kidney, bone marrow

                                                                                    scans; diagnosis of damaged heart

                                                                                    muscles

 

53I131           Iodine-131                                              Diagnosis of thyroid malfunction;

                                                                                    treatment of hyperthyroidism and

                                                                                    thyroid cancer

80Hg197         Mercury-197                                           Kidney scan              

 

 

9.12     THE TRANSURANIUM ELEMENTS:  PREPARATION  

 

  93      Neptunium      (Np)                 92U238 + 0n1    ® 93Np239 + -1b0           

  94      Plutonium       (Pu)                 93Np239           ® 94Pu239 + -1b0

 

  95      Americium     (Am)                94Pu239 + 0n1     ® 95Am240 + -1b0

  96      Curium           (Cm)                    94Pu239 + 2He4   ® 96Cm242 + 0n1

 

  97      Berkelium       (Bk)                95Am241 + 2He4 ® 97Bk243 + 2 0n1

  98      Californium    (Cf)                  96Cm242 + 2He4 ® 98Cf245  + 0n1

 

  99      Einsteinium    (Es)               92U238 + 15 0n1  ® 99Es253  + 7 -1b0

100     Fermium         (Fm)               92U238 + 17 0n1  ® 100Fm255 + 8 -1b0

 

101     Mendelevium (Md)                 99Es2532He4  ® 101Md256 + 0n1

102     Nobelium        (No)                96Cm246 + 6C12  ® 102No254  + 4 0n1

 

103     Lawrencium   (Lr)                  98Cf252   + 5B10  ® 103Lr257   + 5 0n1

104     Rutherfordiu   (Rf)                  98Cf249   + 6C12  ® 104Rf257   + 4 0n1

 

105     Dubnium        (Db)                 98Cf249   + 7N15  ® 105Db260  + 4 0n1

106     Seaborgium   (Sg)                  98Cf249   + 8O18  ®  106Sg263   + 4 0n1

 

107     Bohrium         (Bh)                 83Bi209   + 24Cr54 ® 107Bh262  +    0n1

108     Hassium         (Hs)                82Pb208   + 26Fe58  ® 108Hs265    +    0n1

 

109     Meitnerium     (Mt)                 83Bi209   + 26Fe58 ® 109Mt266   +     0n1

110     Ununnilium     (Uun)                   82Pb208  + 28Ni62  ® 110Uun269 +     0n1

 

111     Unununium     (Uuu)               83Bi209   + 28Ni64  ® 111Uuu272 +     0n1

112     Ununbium       (Uub)               82Pb208   + 30Zn70 ®  112Uub277 +     0n1

 

 

9.12  NUCLEAR FISSION.  ATOMIC ENERGY

 

            1930—Fermi, Hahn, Meitner, Strassman

 

            92U235  +  0n1 ®  56Ba139  + 36Kr94  +  3 0n1 + g + energy

 

            Chain reactions:       

                                    uncontrolled = A- bomb

                                    controlled = reactors  (boron control rods)

                                                electricity from steam generated (10% U.S. total)

Where does the energy come from?

            E = mc2

                E = (1.00 g)(2.99 x 1010 cm/sec)2

                     = 8.94 x 1020 g-cm2/sec2

               = 8.94 x 1020 ergs

               = 8.94 x 1013 Joules

            (enough energy to boil 34 000 000 L of water)

 

When U-235 fissions the mass loss is < g per mole:

                        2.0 x 1013 J/mole

 

A small bomb, equivalent to 20,000 tons of TNT produces:

( 20,000 tons TNT )( 4 x 109 J )   =  8 x 1013 J

                                                        ton TNT

 

Thus, the critical mass for an atomic bomb becomes:

 

            8  x 1013 J    x  235 g U-235  =  1 x 103 g  = 1 kg = 2.2 lbs

                                   2.0 x 1013 J

 

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