fission

Examples of fission in the following topics:

• Nuclear Fission

  • Nuclear fission is a process by which the nucleus of an atom is split into two or more smaller nuclei, known as fission products.
  • Most fissions are binary fissions that produce two charged fragments.
  • These nuclei are called unstable, and this instability can result in radiation and fission.
  • In order to initiate fission, a high-energy neutron is directed towards a nucleus, such as 235U.
  • While nuclear fission can occur without this neutron bombardment, in what would be termed spontaneous fission, this is a rare occurrence; most fission reactions, especially those utilized for energy and weaponry, occur via neutron bombardment.

• The Hydrogen Bomb

  • The hydrogen bomb is a nuclear weapon that uses a mixture of fission and fusion to produce a massive explosion.
  • The only two nuclear weapons that have been used were both fission-based.
  • The nuclear fusion releases neutrons much faster than a fission reaction, and these neutrons then bombard the remaining fissile fuel, causing it to undergo fission much more rapidly.
  • Radiation from a primary fission bomb compresses a secondary section containing both fission and fusion fuel.
  • The compressed secondary is heated from within by a second fission explosion.

• The Atomic Bomb

  • Atomic bombs are nuclear weapons that use the energetic output of nuclear fission to produce massive explosions.
  • Atomic bombs are nuclear weapons that use the energetic output of nuclear fission to produce massive explosions.
  • These bombs are in contrast to hydrogen bombs, which use both fission and fusion to power their greater explosive potential.
  • On August 6th, 1945, a uranium gun-type fission bomb code-named "Little Boy" was detonated over the Japanese city of Hiroshima.
  • Fission can be self-sustaining because it produces more neutrons with the speed required to cause new fissions.

• Nuclear Reactors

  • The energy released from nuclear fission can be harnessed to make electricity with a nuclear reactor.
  • When a large, fissile atomic nucleus such as uranium-235 or plutonium-239 absorbs a neutron, it may undergo nuclear fission.
  • This chain reaction can be controlled using neutron poisons and neutron moderators to change the portion of neutrons that can cause more fissions.
  • Nuclear reactors generally have automatic and manual systems to shut the fission reaction down if unsafe conditions are detected.
  • A possible nuclear fission chain reaction.

• Fusion Reactors

  • This is similar to the process used in fossil fuel and nuclear fission power stations.
  • Above this atomic mass, energy will generally be released by nuclear fission reactions; below this mass, energy will be released by fusion.

• Nuclear Binding Energy and Mass Defect

  • Nuclear binding energy is also used to determine whether fission or fusion will be a favorable process.
  • Elements heavier than iron-56 will generally release energy upon fission, as the lighter elements produced contain greater nuclear binding energy.

• Present Sources of Energy

  • Nuclear (fission) power stations, excluding the contribution from naval nuclear fission reactors, provided about 5.7% of the world's energy and 13% of the world's electricity in 2012.

• RNA and Protein Synthesis

  • In order for bacteria to divide by binary fission and increase their size following division, links in the peptidoglycan must be broken, new peptidoglycan monomers must be inserted, and the peptide cross links must be resealed.