Your SlideShare is downloading. ×
  • Like
Nuclear Chemistry Powerpoint
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Now you can save presentations on your phone or tablet

Available for both IPhone and Android

Text the download link to your phone

Standard text messaging rates apply

Nuclear Chemistry Powerpoint

  • 11,563 views
Published

From Sir Paz

From Sir Paz

Published in Technology , Business
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads

Views

Total Views
11,563
On SlideShare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
366
Comments
0
Likes
2

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Nuclear Chemistry
  • 2. Radioactivity – spontaneous emission of particles and or radiation
    (proposed by Marie Curie)
    • Three types of ray are produced by the decay, or breakdown, of radioactive
    substances
    A. Alpha rays ( α ) – consist of positively charged particles called alpha particles and therefore are deflected by the positively charged plate.
    B. Beta rays ( β ) – or beta particles – are electrons and deflected by negatively charged plate
    C. Gamma rays ( γ ) – have no charged and are not affected by an external electric field or magnetic field
  • 3. Lead block
    Radioactive substance

    a
    g
    b
    +
  • 4. Lead block

    +
  • 5. Lead block
    Radioactive substance

    a
    +
  • 6. Lead block
    Radioactive substance

    b
    +
  • 7. Lead block
    g
    Radioactive substance

    +
  • 8. Lead block
    Radioactive substance

    a
    g
    b
    +
  • 9.
  • 10. A
    X
    Mass Number
    Element Symbol
    Z
    Atomic Number
    a particle
    proton
    neutron
    electron
    positron
    or
    or
    1p
    1H
    0b
    0e
    or
    1
    1
    +1
    1n
    0e
    +1
    0b
    0
    -1
    -1
    4a
    4He
    or
    2
    2
    Atomic number (Z) = number of protons in nucleus
    Mass number (A) = number of protons + number of neutrons
    = atomic number (Z) + number of neutrons
    A
    1
    1
    0
    0
    4
    1
    0
    -1
    +1
    2
    Z
    23.1
  • 11. +
    +
    + 2
    +
    +
    + 2
    1n
    1n
    1n
    1n
    96
    96
    0
    0
    0
    0
    Rb
    Rb
    37
    37
    235
    138
    235
    138
    U
    Cs
    U
    Cs
    92
    55
    92
    55
    Balancing Nuclear Equations
    Conserve mass number (A).
    The sum of protons plus neutrons in the products must equal the sum of protons plus neutrons in the reactants.
    235 + 1 = 138 + 96 + 2x1
    Conserve atomic number (Z) or nuclear charge.
    The sum of nuclear charges in the products must equal the sum of nuclear charges in the reactants.
    92 + 0 = 55 + 37 + 2x0
    23.1
  • 12. or
    alpha particle -
    212Po 4He + AX
    2
    Z
    84
    212Po 4He + 208Pb
    2
    82
    84
    4a
    4He
    2
    2
    212Po decays by alpha emission. Write the balanced nuclear equation for the decay of 212Po.
    212 = 4 + A
    A = 208
    84 = 2 + Z
    Z = 82
    23.1
  • 13. 23.1
  • 14. I. Nuclear Stability and Radioactive Decay
  • 15. X
    Y
    n/p too large
    beta decay
    n/p too small
    positron decay or electron capture
    23.2
  • 16.
  • 17.
  • 18. Predicting the mode of decay
    High n/p ratio (too many neutrons; lie above band of stability) --- undergoes beta decay
    Low n/p ratio (neutron poor; lie below band of stability) --- positron decay or electron capture
    Heavy nuclides ( Z > 83) --- alpha decay
  • 19. II. Nuclear Transmutations
    • Nuclear reactions that are induced in a way that nucleus is struck by a neutron or by another nucleus (nuclear bombardment)
    Positive ion bombardment
    - alpha particle is the most commonly used positive ion
    - uses accelerators
    Examples:
    147 N + 42 He -> 178 O + 11H
    94Be + 42 He -> 126 C + 10n
    Neutron bombardment
    - neutron is bombarded to a nucleus to form a new nucleus
    - most commonly used in the transmutation to form synthetic isotopes because neutron are neutral, they are not repelled by nucleus
    Example:
    5826 Fe + 10 n -> 5926 Fe -> 5927 Co + 0-1 e
  • 20. 5
    +
    +
    +
    +
    + 0-1 e
    +
    +
    4He
    1n
    1n
    0e
    14N
    1n
    2
    0
    -1
    7
    0
    0
    239
    242
    238
    239
    239
    239
    238
    247
    Pu
    Cm
    U
    U
    Pu
    Np
    U
    Es
    94
    96
    92
    92
    94
    93
    92
    99
    Transuranium elements
    • Element with atomic numbers above 92
    • 21. Produced using artificial transmutations, either by:
    alpha bombardment
    neutron bombardment
    bombardment from other nuclei
    Examples:
    a.
    b.
    c.
  • 22. III. Nuclear Energy
    Recall:
    Nucleus is composed of proton and neutron
    Then, is the mass of an atom equal to the total mass of all the proton plus the total mass of all the neutron?
    Example for a He atom:
    Total mass of the subatomic particles
    = mass of 2 p+ + mass of 2n0
    = 2 ( 1.00728 amu ) + 2 (1.00867 amu)
    = 4.03190 amu
    And atomic weight of He-4 is 4.00150
    Why does the mass differ if the atomic mass = number of protons + number of neutrons?
  • 23. Mass defect
    -mass difference due to the release of energy
    -this mass can be calculated using Einstein’s equation E =mc2
    2 11 H + 2 20 H -> 42 He + energy
    Therefore:
    -energy is released upon the formation of a nucleus from the constituent protons and neutrons
    -the nucleus is lower in energy than the component parts.
    -The energy released is a measure of the stability of the nucleus. Taking the reverse of the equation:
    42He + energy -> 2 11 H + 2 20 n
  • 24. Therefore,
    -energy is released to break up the nucleus into its component parts. This is called the nuclear binding energy.
    -the higher the binding energy, the stable the nuclei.
    -isotopes with high binding energy and most stable are those in the mass range 50-60.
  • 25. Nuclear binding energy per nucleon vs Mass number
    nuclear binding energy
    nucleon
    nuclear stability
    23.2
  • 26. -The plot shows the use of nuclear reactions as source of energy.
    -energy is released in a process which goes from a higher energy state (less stable, low binding energy) to a low energy state (more stable, high binding energy).
    -Using the plot, there are two ways in which energy can be released in nuclear reactions:
    a. Fission – splitting of a heavy nucleus into smaller nuclei
    b. Fusion – combining of two light nuclei to form a heavier, more stable nucleus.
  • 27. BE + 19F 91p + 101n
    0
    9
    1
    binding energy per nucleon =
    binding energy
    number of nucleons
    2.37 x 10-11 J
    19 nucleons
    =
    Nuclear binding energy (BE) is the energy required to break up a nucleus into its component protons and neutrons.
    E = mc2
    BE = 9 x (p mass) + 10 x (n mass) – 19F mass
    BE (amu) = 9 x 1.007825 + 10 x 1.008665 – 18.9984
    BE = 0.1587 amu
    1 amu = 1.49 x 10-10 J
    BE = 2.37 x 10-11J
    = 1.25 x 10-12 J
    23.2
  • 28. 23.3
  • 29. 14N + 1n 14C + 1H
    0
    7
    1
    6
    14C 14N + 0b + n
    6
    7
    -1
    238U 206Pb + 8 4a + 6 0b
    92
    -1
    82
    2
    Radiocarbon Dating
    t½ = 5730 years
    Uranium-238 Dating
    t½ = 4.51 x 109 years
    23.3
  • 30. 14N + 4a17O + 1p
    7
    2
    1
    8
    27Al + 4a30P + 1n
    13
    2
    0
    15
    14N + 1p 11C + 4a
    7
    1
    2
    6
    Cyclotron Particle Accelerator
    Nuclear Transmutation
    23.4
  • 31. Nuclear Transmutation
    23.4
  • 32. 235U + 1n 90Sr + 143Xe + 31n + Energy
    38
    0
    0
    54
    92
    Nuclear Fission
    Energy = [mass 235U + mass n – (mass 90Sr + mass 143Xe + 3 x mass n )] x c2
    Energy = 3.3 x 10-11J per 235U
    = 2.0 x 1013 J per mole 235U
    Combustion of 1 ton of coal = 5 x 107 J
    23.5
  • 33. 235U + 1n 90Sr + 143Xe + 31n + Energy
    38
    0
    0
    54
    92
    Nuclear Fission
    Representative fission reaction
    23.5
  • 34. Non-critical
    Critical
    Nuclear Fission
    Nuclear chain reaction is a self-sustaining sequence of nuclear fission reactions.
    The minimum mass of fissionable material required to generate a self-sustaining nuclear chain reaction is the critical mass.
    23.5
  • 35. Nuclear Fission
    Schematic diagram of a nuclear fission reactor
    23.5
  • 36. 35,000 tons SO2
    4.5 x 106 tons CO2
    70 ft3 vitrified waste
    3.5 x 106
    ft3 ash
    1,000 MW coal-fired
    power plant
    1,000 MW nuclear
    power plant
    Nuclear Fission
    Annual Waste Production
    23.5
  • 37. Nuclear Fission
    Hazards of the radioactivities in spent fuel compared to uranium ore
    23.5
    From “Science, Society and America’s Nuclear Waste,” DOE/RW-0361 TG
  • 38. 2H + 2H 3H + 1H
    1
    1
    1
    1
    2H + 3H 4He + 1n
    2
    1
    0
    1
    6Li + 2H 2 4He
    2
    3
    1
    Nuclear Fusion
    Fusion Reaction
    Energy Released
    6.3 x 10-13 J
    2.8 x 10-12 J
    3.6 x 10-12 J
    Tokamak magnetic plasma confinement
    23.6
  • 39. Radioisotopes in Medicine
    • 1 out of every 3 hospital patients will undergo a nuclear medicine procedure
    • 40. 24Na, t½ = 14.8 hr, b emitter, blood-flow tracer
    • 41. 131I, t½ = 14.8 hr, b emitter, thyroid gland activity
    • 42. 123I, t½ = 13.3 hr, g-ray emitter, brain imaging
    • 43. 18F, t½ = 1.8 hr, b+ emitter, positron emission tomography
    • 44. 99mTc, t½ = 6 hr, g-ray emitter, imaging agent
    Brain images with 123I-labeled compound
    23.7
  • 45. Geiger-Müller Counter
    23.7
  • 46. Biological Effects of Radiation
    Radiation absorbed dose (rad)
    1 rad = 1 x 10-5 J/g of material
    Roentgen equivalent for man (rem)
    1 rem = 1 rad x Q
    Quality Factor
    g-ray = 1
    b = 1
    a = 20
    23.8
  • 47. Chemistry In Action: Food Irradiation