conservation of mass

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Related to conservation of mass: law of conservation of mass

Conservation of mass

The notion that mass, or matter, can be neither created nor destroyed. According to conservation of mass, reactions and interactions which change the properties of substances leave unchanged their total mass; for instance, when charcoal burns, the mass of all of the products of combustion, such as ashes, soot, and gases, equals the original mass of charcoal and the oxygen with which it reacted.

The special theory of relativity of Albert Einstein, which has been verified by experiment, has shown, however, that the mass of a body changes as the energy possessed by the body changes. Such changes in mass are too small to be detected except in subatomic phenomena. Furthermore, matter may be created, for instance, by the materialization of a photon (quantum of electromagnetic energy) into an electron-positron pair; or it may be destroyed, by the annihilation of this pair of elementary particles to produce a pair of photons. See Electron-positron pair production, Relativity

conservation of mass

[‚kän·sər′vā·shən əv ′mas]
The notion that mass can neither be created nor destroyed; it is violated by many microscopic phenomena.
References in periodicals archive ?
The conservation of mass, momentum and energy equations are applied to the two interacting control volumes.
In comparison, COSMO solves the conservation of mass, momentum, and energy equations applied to a large numbers of differential cells in the vertical spaces.
The theoretical density obtained by conservation of mass is too large by a factor of order 200 at redshift 5.
In a similar manner that conservation of mass links areas and velocities, Bernoulli's equation links velocities and static pressures, when applied to a diffuser or a nozzle.
The interface development and material distribution during the cavity filling can be accurately determined by enforcing the extra local mass conservation at each fluid subdomain, apart from the global conservation of mass at the whole cavity domain.
In reality, it takes much more than one activity for young learners to assimilate such understanding of the conservation of mass.
A "toolkit" for modelers is provided, including general mathematical functions, and cornerstone principles such as feedback, conservation of mass, and units checking.
Lavoisier had advanced the law of conservation of mass (see 1789) and before that there had been the law of conservation of momentum (see 1668).
Based on the conservation of mass, the resulting average thickness of the formed part will be the original thickness multiplied by the strech ratio.
3", (2007) is incorporated to solve the differential equations governing the conservation of mass, three momentum and energy in the processing of airflow distribution.
Pretests and posttests were used to measure the change in students' understanding of chemical reactions, conservation of mass, and biological growth.

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