fission

fissionfission of a uranium nucleus

fis·sion

F0150600 (fĭsh′ən, fĭzh′-)n.1. The act or process of splitting into parts.2. A nuclear reaction in which an atomic nucleus, especially a heavy nucleus, such as an isotope of uranium, splits into fragments, usually two fragments of comparable but unequal mass, and releases a few neutrons and about 100 million electron volts of energy. Nuclear fission may occur spontaneously or may be induced by the absorption of a neutron, which can initiate a nuclear chain reaction.3. Biology An asexual reproductive process in which a unicellular organism divides into two or more independently maturing daughter cells.v. fis·sioned, fis·sion·ing, fis·sions v.tr. To cause (an atom) to undergo fission.v.intr. To undergo fission.

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[Latin fissiō, fissiōn-, a cleaving, from fissus, split; see fissi-.]

fission

(ˈfɪʃən) n1. the act or process of splitting or breaking into parts2. (Biology) 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 cells3. (General Physics) short for nuclear fission[C19: from Latin fissiō a cleaving]

fis•sion

(ˈfɪʃ ən)

n. 1. the act of cleaving or splitting into parts. 2. the splitting of the nucleus of an atom into nuclei of lighter atoms, accompanied by the release of energy. 3. the division of a biological organism into new organisms as a process of reproduction. v.t. 4. to cause (an atom) to undergo fission. Compare fusion (def. 4). [1835–45; < Latin fissiō splitting, cleaving]

fis·sion

(fĭsh′ən)1. The splitting of the nucleus of an atom into two or more nuclei. The splitting occurs either spontaneously, because the nucleus has many neutrons and is unstable, or because the nucleus has collided with a free-moving neutron. The splitting of a nucleus releases one or more neutrons and energy in the form of radiation. See Note at fusion.2. A reproductive process in which a single cell splits to form two independent cells that later grow to full size. Bacteria and other single-celled organisms usually reproduce by means of fission. Also called binary fission.

fission

The process whereby the nucleus of a heavy element splits into (generally) two nuclei of lighter elements, with the release of substantial amounts of energy.

fission

1. A process (spontaneous or induced) during which a heavy atomic nucleus disintegrates into two lighter atoms which together have less mass than the total initial material. This lost mass is converted to energy, the amount is given by Einstein’s equation E=mc2.2. The splitting of an atom’s nucleus to release subatomic particles and energy.

Thesaurus

Noun	1.	fission - reproduction of some unicellular organisms by division of the cell into two more or less equal partsagamogenesis, asexual reproduction - reproduction without the fusion of gametesschizogony - asexual reproduction by multiple fission; characteristic of many sporozoan protozoans
	2.	fission - a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energynuclear fissionnuclear reaction - (physics) a process that alters the energy or structure or composition of atomic nuclei

fission

noun splitting, parting, breaking, division, rending, rupture, cleavage, schism, scission a fission in the earth's crust

Translations

裂变

fission

noun : nuclear fission (ˈfiʃən) the splitting of the nuclei of atoms. 分裂（核分裂） 裂变