2.  Take a large atom and impact the nucleus with a particle.  Split the atom releasing high energy, more high energy neutrons, and two daughter nuclides.  Fission occurs only rarely in nature. Alpha decay is much more common.

3.  Elements with an atomic number greater than 80 are capable of undergoing fission.  235 92 U absorbs a neutron, 1 0 n, temporarily producing unstable 236 92 U.  Almost immediately 236 92 U splits into two more stable daughter nuclides plus large amounts of energy and two to three fast neutrons depending on the reaction.

4.  The fast neutrons produced by fission fly off to impact other atoms of 235 92 U resulting in a chain reaction.  The fission of uranium-235 releases ~200MeV. That equals ~100x energy release by burning a coal molecule.

5.  Fissile: atoms ( 235 U or 239 Pu)that are capable of undergoing fission when an atom captures a thermal slower neutron.  Fissionable: atoms ( 238 U)able to undergo fission when bombarded with high energy neutrons such as in a thermonuclear weapon, bomb.  Nuclear fuels: elements that can sustain a fission chain reaction such as uranium-235 and plutonium- 239.  Spontaneous fission: the slowly occurring process of fission in nuclear fuels unaltered by human intervention.  Critical mass: enough nuclear fuel present and emitting neutrons in quantities to sustain a chain reaction.

6.  Once the fission reaction is initiated, the high energy neutrons released keep the reaction going. This is a chain reaction.  The mousetrap model. › http://www.youtube.com/watch?v=0v8i4v1 mieU Student project 2:54 minutes http://www.youtube.com/watch?v=0v8i4v1 mieU › http://www.youtube.com/watch?v=vjqIJW_ Qr3c NatSciDemo 2:28 minutes http://www.youtube.com/watch?v=vjqIJW_ Qr3c

7.  A coal fired plant and a nuclear plant share the same power generation type: conversion of heat to electricity via pressurized steam.  The fission reaction releases energy which is absorbed by water converting some of the water to steam.  Steam is used to drive the turbine connected to a generator.

9. http://www.youtube.com/watch?v=CGRx 2cPjUXMhttp://www.youtube.com/watch?v=CGRx 2cPjUXM Navy Film of Bikini Crossroads Test A bomb typically uses a contained explosion or impact to induce a chain reaction. No controls limit the progress of the reaction.

10.  Fusion reactions are the combining of two nuclei to form a more massive nucleus.  Many fusion reactions release large amounts of energy. › An example is the combining of two isotopes of hydrogen (tritium and deuterium) to form helium and a neutron plus a large amount of kinetic energy in the reaction products: 3H + 2H  4He + n + 17.6 MeV

11.  http://www.youtube.com/watch?featur e=endscreen&v=yTkojROg- t8&NR=1&safety_mode=true&persist_saf ety_mode=1&safe=active Best of Science, Fission and Fusion 8:38 minutes http://www.youtube.com/watch?featur e=endscreen&v=yTkojROg- t8&NR=1&safety_mode=true&persist_saf ety_mode=1&safe=active

13.  http://www.lbl.gov/abc/wallchart/teach ersguide/contents.html DOE Teacher’s Guide http://www.lbl.gov/abc/wallchart/teach ersguide/contents.html