Warmup (5 minutes) 1.Write the equation that shows phosphorus-32 going through positron emission...
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Transcript of Warmup (5 minutes) 1.Write the equation that shows phosphorus-32 going through positron emission...
Warmup (5 minutes)
1. Write the equation that shows phosphorus-32 going through positron emission while emitting a gamma ray.
2. If Po-212 goes through alpha decay, then alpha decay again, what isotope will be present?
32P 0e + 0γ + 32Si15 +1 0 14
Fission and Fusionand some other stuff
Sometimes an unstable isotope is REALLY radioactive…one simple nuclear decay is NOT enough to make it stable…it must go through a series of reactions to make it stable again.
Po21084
Pb20682+He4
2 He42 +Hg202
80
212 208
202
• The decay series for U238
92Alpha Decay
Beta Decay Beta DecayAlpha Decay
Alpha DecayAlpha Decay Alpha Decay
Alpha DecayBeta DecayBeta Decay
Alpha Decay Beta Decay Beta Decay
Alpha DecayPb206
82
FUSIONvolunteer to read?
•Stars, which are gigantic comparedeven to planets, make up most of thematter in the universe.•Most suns (stars) are made of mostly hydrogen. Hydrogen is really just a proton (sometimes with an extra neutron or two). There have always been lots of solo protons in the universe.•We, however, are made mostly of carbon and depend desperately on oxygen. How did enough protons happen to come together into heavier, more complex atoms so that we could exist?
FUSION continued•When stars fuse hydrogen, heavier atoms and vast amounts of energy are created
•When a star runs out of hydrogen, it starts to fuse other things until it 1. runs out of fuel 2. goes cold or 3. gets so dense that the pressure inside blows it apart (nova or supernova!).
•If the star blows apart, all those heavier atoms it created in its core now scatter into the cosmos to eventually collect to make more stars and planets.
•Our planet owes all its amazing materials to the fusion reactions of long blown-apart stars in other parts of the galaxy. Without fusion, life on earth, life anywhere, would be impossible.
Nuclear Fusion: the process of combining light nuclei to form a heavier nucleus
(hydrogen isotopes)
Like in Spiderman 2!
2H + 3H 4He + 1n +
1 1 2 0 Energy
2H + 2H 3H + 1H1 1 1 1
Fusion Reaction Energy Released
2H + 3H 4He + 1n1 1 2 0
6Li + 2H 2 4He3 1 2
6.3 x 10-13 J (per reaction)
2.8 x 10-12 J
3.6 x 10-12 J
3. Write balanced equations showing the fusion of:
(you may have to fill in missing products)
a. 2 deuterium atoms (hydrogen-2) to release a proton
b. Deuterium with tritium to produce helium-4
c. Lithium-6 and deuterium to produce helium
Energy released by 1 megaton hydrogen bomb: 4 x 1015 J
Energy output of our sun: 1034 J per year
Nuclear Fission: Nuclear Fission: splitting of a nucleus into 2 smaller nuclei; usually involves a neutron hitting a
large, unstable nucleus just right.4. Write an equation showing this fission reaction
235U + 1n 90Sr + 143Xe + 31n + Energy92 54380 0
Energy = [mass 235U + mass n – (mass 90Sr + mass 143Xe + 3 x mass n )] x c2
= 2.0 x 1013 J per mole 235U
Combustion of 1 ton of coal = 5 x 107 J
E = mc2 E = energy m = massC = speed of light = 3.00 x 108m/s)A little mass can create a huge amount of energy, which can be calculated (complicated):
Fission Chain Reaction: is a self-sustaining sequence of nuclear fission reactions.
Fission is the science behind the Atomic Bomb and Nuclear Power plants
Fusion is the science behind the hydrogen bomb
Nuclear Fission & Nuclear Fission & POWERPOWER
Currently about 103 nuclear Currently about 103 nuclear
power plants in the U.S. and power plants in the U.S. and
about 435 worldwide.about 435 worldwide.
17% of the world’s energy 17% of the world’s energy
comes from nuclear power. But comes from nuclear power. But
IS nuclear power the best IS nuclear power the best
energy source?energy source?
Dangers of Radiation Exposure
Genetic Damage : radiation causes damage to reproductive cells or organs
* damage to future offspring
Somatic Damage : has an impact on the organism
*seen immediately or in the future
Extent of damage depends on:Energy and penetration of radiation
(Gamma >> Beta > Alpha)The half-life of the particular isotopeAmount/duration of exposure
Marie Curie and Radium
Used to make things glow at low temps
It glows because Its emitting photons
• In extreme cases of Radiation sickness involve hair loss, vomiting of blood, intestinal failure, sores, hemorrhaging, etc
Too much radiation causes burns, mutations, and cancers
Some interesting Mutations