NuclearNuclear ChemistryChemistry

Nuclear FissionPrepared By:

Julie S.R.Julie S.R.Roll No: 9Roll No: 9

Physical Science,GCTE,TrivandrumPhysical Science,GCTE,Trivandrum

Involve changes in the composition of nuclei

Accompanied by the release of tremendous amounts of energy

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In nuclear fission, a large nucleus is bombarded with a small

particle the nucleus splits into smaller nuclei and

several neutrons large amounts of energy are released

Nuclear FissionNuclear Fission

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Nuclear FissionNuclear Fission

When a neutron bombards U-235, an unstable nucleus of U-236 forms and

undergoes fission (splits) smaller nuclei are produced such as Kr-91 and

Ba-142 neutrons are released to bombard more 235U

• some elements undergo fission spontaneously

• some elements can be induced to undergo fission when bombarded with other particles (e.g. neutrons)

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Nuclear Fission Diagram and Nuclear Fission Diagram and

EquationEquation

1 235 236 91 142 10 92 92 36 56 0 + U U Kr + Ba + 3 + energyn n

The Atomic Bomb The Atomic Bomb (FISSION)(FISSION)

• when the nucleus of U-235 splits, 2 isotopes are formed, plus neutrons are emitted

• these neutrons collide with other U-235 atoms, causing them to undergo fission; they release neutrons, and so on…

• The result - CHAIN REACTION!!

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Chain ReactionChain Reaction

A chain reaction occurs when a critical mass

of uranium undergoes fission

releasing a large amount of heat and energy that produces an atomic explosion

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Nuclear Power Nuclear Power PlantsPlantsIn nuclear power plants,

fission is used to produce energy control rods in the reactor absorb neutrons

to slow and control the chain reactions of fission

1) Fission heats up water in vessel and heat is carried away.

2) This heat is used to heat up water in a second system, which turns into steam.

3) Steam turns turbine of a generator.4) Generator makes electricity.

Thank YouThank You