fission

American  

[fish-uhn] / ˈfɪʃ ən /

noun

1. the act of cleaving or splitting into parts.

2. Also called nuclear fission.  Physics. the splitting of the nucleus of an atom into nuclei of lighter atoms, accompanied by the release of energy.

3. Biology. the division of an organism into new organisms as a process of reproduction.

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verb (used without object)

1. Physics. to undergo fission.

verb (used with object)

1. Physics. to cause to undergo fission.

fission British  

/ ˈfɪʃən /

noun

1. the act or process of splitting or breaking into parts

2. biology a form of asexual reproduction in single-celled animals and plants involving a division into two or more equal parts that develop into new cells

3. short for nuclear fission

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fission Scientific  

/ fĭsh′ən /

1. The splitting of an unstable atomic nucleus into two or more nuclei. Fission occurs spontaneously, generally when a nucleus has an excess of neutrons, resulting in the inability of the strong force to bind the protons and neutrons together. The fission reaction used in many nuclear reactors and bombs involves the absorption of neutrons by uranium-235 nuclei, which immediately undergo fission, releasing energy and fast neutrons.

2. Compare fusion

3. A process of asexual reproduction in which a single cell splits to form two identical, independent cells. In fission, the chromosomal DNA replicates before the cell divides. Most bacteria and other prokaryotes reproduce by means of fission.

4. Also called binary fission

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Etymology

Origin of fission

First recorded in 1835–45; from Latin fissiōn- (stem of fissiō ) “a splitting, dividing,” equivalent to fiss(us) “divided” + -iōn- noun-forming suffix; fissi-, -ion; fission def. 2 was first recorded in 1935–40

Example Sentences

It generates four times as much energy as fission, according to the International Atomic Energy Agency.

From Barron's

Today, all of the world’s nuclear energy is generated from fission, the process of splitting the nucleus of an atom.

From Barron's

The fusion process creates energy by joining atoms together, while nuclear fission creates energy when atoms are split apart.

From The Wall Street Journal

But nuclear fission does create waste, in the form of radioactive isotopes.

From Literature

As part of its energy surge, China has pushed rapid investment into the only technology that currently can decarbonize the planet at scale: nuclear fission and fusion.

From The Wall Street Journal