How Can We Change Lead Into Gold?

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How Can We Change Lead Into Gold?
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What Element is This?
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The Four Universal Forces

• Gravitational force
• Electromagnetism
• Weak
• Strong

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Who Discovered Radioactivity?

• In 1896, Henri Becquerel, along with Pierre and
  Marie Curie discovered radioactive waves by
  placing a rock containing Uranium on a
  photographic plate. They shared the Nobel Prize
  in 1903.

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What is Radioactive Decay?

• Radioactive decay is the set of various processes
  by which unstable atomic nuclei emit subatomic
  particles (radiation).
• Decay is said to occur in the parent nucleus and
  produces a daughter nucleus.

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Types of Particles
Identity Symbol Charge Mass (amu)
Helium (Alpha) 4 a 2 2 4.001056
Electron (Beta) 0 ß -1 -1 0.000549
Photon (gamma) 0 ? 0 N/A N/A
Neutron 1 n 0 0 1.008665
Proton 1 p 1 1 1.007276
Positron 0 ß 1 1 0.000549
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What are their properties?
Alpha largest particle, can be stopped by
paper Beta can be stopped by a few layers of
clothing Gamma most penetrating, stopped by lead
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How To Solve Nuclear Decay Problems?
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How Can We Date Rocks?
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Half-life The time it takes for half the element
to decay
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Half Life Calculations

• To calculate the ½ life
• t1/2 log 0.5___
• log(No/N)
• N amount remaining
• No amount you started with
• t time elapsed
• t1/2 half life

x t
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Half - Life

• The half life of I-123 is 13 hours. How much of
  a 64 mg sample is left after 26 hours?
• No 64 mg
• t 26 hours
• t1/2 13 hours
• How many half lives have passed?
• N 64 x (0.5)2
• N 16 mg remaining

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Half - Life
Isotope Half - Life
Carbon-15 2.4 seconds
Radium-224 3.6 days
Radium-223 12 days
Iodine-125 60 days
Carbon-14 5700 years
Uranium-235 710,000,000 years
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What is the difference between Fission and Fusion?
Fission Splitting of atomic nucleus (nuclear
power plant) Fusion Fusing of atomic nuclei
(sun) Both release large amounts of energy
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What Are The Uses of Radioactivity?

• There are many practical applications to the use
  of radioactivity/radiation.
• Radioactive sources are used to study living
  organisms
• To diagnose and treat diseases
• To sterilize medical instruments and food
• To produce energy for heat and electric power
• To monitor various steps in all types of
  industrial processes.
• To determine age of fossils