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? 32 P  0 e + 0 γ + 32 Si

Fission and Fusion and 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

The decay series for Alpha Decay Beta Decay Alpha Decay Beta Decay Alpha DecayBeta Decay Alpha Decay

FUSION volunteer to read? Stars, which are gigantic compared even to planets, make up most of the matter 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! 2 H + 3 H  4 He + 1 n Energy

2 H + 2 H 3 H + 1 H Fusion ReactionEnergy Released 2 H + 3 H 4 He + 1 n Li + 2 H 2 4 He x J (per reaction) 2.8 x J 3.6 x 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 J Energy output of our sun: 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

235 U + 1 n 90 Sr Xe n + Energy Energy = [mass 235 U + mass n – (mass 90 Sr + mass 143 Xe + 3 x mass n )] x c 2 = 2.0 x J per mole 235 U Combustion of 1 ton of coal = 5 x 10 7 J E = mc 2 E = energym = mass C = speed of light = 3.00 x 10 8 m/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 & POWER Currently about 103 nuclear power plants in the U.S. and about 435 worldwide. 17% of the world’s energy comes from nuclear power. But IS nuclear power the best 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 isotope  Amount/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