Nuclear fission

related topics
{acid, form, water}
{ship, engine, design}
{math, energy, light}
{war, force, army}
{theory, work, human}
{day, year, event}
{work, book, publish}
{city, population, household}
{school, student, university}

In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), as well. Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). For fission to produce energy, the total binding energy of the resulting elements has to be higher than that of the starting element. Fission is a form of nuclear transmutation because the resulting fragments are not the same element as the original atom.

Nuclear fission produces energy for nuclear power and to drive the explosion of nuclear weapons. Both uses are made possible because certain substances called nuclear fuels undergo fission when struck by free neutrons and in turn generate neutrons when they break apart. This makes possible a self-sustaining chain reaction that releases energy at a controlled rate in a nuclear reactor or at a very rapid uncontrolled rate in a nuclear weapon.

The amount of free energy contained in nuclear fuel is millions of times the amount of free energy contained in a similar mass of chemical fuel such as gasoline, making nuclear fission a very tempting source of energy. The products of nuclear fission, however, are on average far more radioactive than the heavy elements which are normally fissioned as fuel, and remain so for significant amounts of time, giving rise to a nuclear waste problem. Concerns over nuclear waste accumulation and over the destructive potential of nuclear weapons may counterbalance the desirable qualities of fission as an energy source, and give rise to ongoing political debate over nuclear power.

Contents

Full article ▸

related documents
Heavy water
Xenon
Acid dissociation constant
Protein
Ozone depletion
Uranium
DNA
Sulfur
Carbon
Alternative biochemistry
Nitrogen
Enzyme
Ethanol
Fusion power
List of food additives, Codex Alimentarius
Photosynthesis
Electron transport chain
Copper
Polymer
Acetic acid
Rutherfordium
Inorganic chemistry
Concrete
Hemoglobin
Radioactive waste
E number
Seaborgium
Oxygen
Hydrogen
Silicon