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Nuclear Chemistry
Radioactive Decay
 Spontaneous breakdown of an atom’s nucleus
 Breakdown results in a lighter nucleus
 Emits electromagnetic radiation
 Nuclear radiation—radiation emitted from nucleus
 Radioactive nuclide– nucleus that goes through
radioactive decay, unstable. (Ex. Uranium
Types of Radioactive Decay
1) Alpha particle (α)
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Consists of 2 protons, 2 neutrons emitted during decay
Helium nucleus ( 24He )—how particle represented
Can be stopped by paper, low energy
Atomic number goes down 2, atomic mass goes down 4.
Equation: 84210 Po  82206 Pb + 24 He
2) Beta particle (β)
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Electron given off during radioactive decay
Can be stopped by lead or glass
Increase in atomic #
Equation: 614 C  714 N + -10 β
3) Gamma Rays
 Has the most energy, only stopped by lead
 Ex. X-Rays
Example 1: Nuclear equation
when an alpha particle emitted
by 21084Po
Example 2:Nuclear equation
when a beta particle emitted by
210 Pb
82
Practice: Alpha Decay
1) Be-9
2) U-238
3) Eu-154
Beta Decay
1) Th-234
2) K-43
Half-Life
 Time period required for half of a radioactive nuclide to
decay.
 Vary depending on the nuclide, unique for each nuclide.
 Ex. 146C has a half-life of 5715. Therefore, if we have
10g of 146C, in 5715 years we will have 5g.
Half-Life Equation
AE = AO * 0.5
t/t(1/2)
AE = Substance amount
A0 = Initial substance amount
t = time elapsed
t1/2 = half-life
Example 1: Plutonium-239 has a half life of 24,110 years.
We have 100g of this substance. How many grams will we
have after 96,440 years?
More on Nuclear
Chemistry
Nuclear Fission
 Nuclear reaction where nuclei are SPLIT
 Nucleus is broken down into a more stable nucleus.
 HUGE amount of energy is released
 Critical mass = minimum number of nuclei that can
provide enough neutrons to maintain chain reaction.
 Nuclear reactors = controlled fission reactions.
**Can induce a nuclear chain reaction!!!
Nuclear Reactors
 Location where controlled fission reactions occur
 Fuel rods in the core contain enriched uranium
 Steam generation
generator
steam turbine
electric
 Control rods take in neutrons so fission is controlled
 Production of radioactive waste
 A TON of water is used to cool the reactors
Nuclear Fusion
 Nuclei having a light mass are joined.
 Combination of light nuclei
 Creates heavy nucleus
 Results in larger, stable nucleus.
 MORE energy released than in nuclear fission !!!
 Hard to control
 Initiated by fission reaction (fission bomb) ---- H bomb
**Type of reaction happening in the sun and stars.
-fuel: hydrogen atom
cu
Applications to Nuclear
Radiation
1) Radioactive Dating
 Age determination of artifact based on presence of radioactive
nuclide
2) Medical Purposes
 Cancer treatments
 Radioactive tracers
3) Food Processing
 Meat exposed to radiation
 Kills microorganisms
Prompt
 We talked about nuclear energy today. Do you support
or disagree with this type of green energy? Support your
answer.
How could we harness the nuclear energy in the sun?
Discuss how we might use nuclear fusion to benefit us.