Uranium-235 Fission Example. If at least one neutron from each fission strikes another U-235 nucleus and initiates fission, then the chain reaction is sustained. If an least one neutron from U-235 fission strikes another nucleus and causes it to fission, then the chain reaction will continue. If the reaction will sustain itself, it is said to be critical, and the mass of U-235 required to produced the critical condition is said to be a critical mass.
http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/U235chn.html
When a nucleus fissions, it splits into several smaller fragments. These fragments, or fission products, are about equal to half the original mass. Two or three neutrons are also emitted. Nuclear Fission. The sum of the masses of these fragments is less than the original mass. This 'missing' mass (about 0.1 percent of the original mass) has been converted into energy according to Einstein's equation. Fission can occur when a nucleus of a heavy atom captures a neutron, or it can happen spontaneously.
http://www.atomicarchive.com/Fission/Fission1.shtml
It's also one of the few elements that can undergo induced fission. Fire a free neutron into a U-235 nucleus and the nucleus will absorb the neutron, become unstable and split immediately. See How Nuclear Radiation Works for complete details. This content is not compatible on this device.
http://science.howstuffworks.com/nuclear-power1.htm
When a nucleus fissions, it splits into several smaller fragments. These fragments, or fission products, are about equal to half the original mass. Two or three neutrons are also emitted. The sum of the masses of these fragments is less than the original mass.
http://www.atomicarchive.com/Fission/Fission1.shtml
The graph of binding energy per nucleon suggests another way of obtaining useful energy from nuclear reactions. Fusing two light nuclei can liberate as much energy as the fission of 235U or 239Pu. The fusion of four protons to form a helium nucleus, two positrons (and two neutrinos), for example, generates 24.7 MeV of energy.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch23/fission.php
The half-life for the spontaneous fission of 238U, for example, is 1016 years, or about two million times longer than the age of our planet! We don't have to wait, however, for slow spontaneous fission reactions to occur.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch23/fission.php
The induced fission of this isotope releases an average of 200 MeV per atom, or 80 million kilojoules per gram of 235U. The attraction of nuclear fission as a source of power can be understood by comparing this value with the 50 kJ/g released when natural gas is burned.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch23/fission.php
Energy From Uranium Fission. If at least one neutron from each fission strikes another U-235 nucleus and initiates fission, then the chain reaction is sustained. If an least one neutron from U-235 fission strikes another nucleus and causes it to fission, then the chain reaction will continue.
http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/U235chn.html
While older plants burn fossil fuels, nuclear plants depend on the heat that occurs during nuclear fission, when one atom splits into two and releases energy. Nuclear fission happens naturally every day. Uranium, for example, constantly undergoes spontaneous fission at a very slow rate. This is why the element emits radiation, and why it's a natural choice for the induced fission that nuclear power plants require. 10 Reasons the Multiverse Is a Real Possibility.
http://science.howstuffworks.com/nuclear-power1.htm
239Pu in the fuel assembly absorbs one of these fast neutrons and undergoes fission with the release of three neutrons. 238U in the fuel then captures one of these neutrons to produce additional 239Pu. The advantage of breeder reactors is obviousthey mean a limitless supply of fuel for nuclear reactors.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch23/fission.php
what happens in a nuclear fission reaction
In a nuclear fission reaction, it splits into several smaller fragments. A nuclear fission reaction splits into several smaller fragments.