half–life
playSimple Definition of half–life
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: the time it takes for a radioactive substance to lose half its radioactivity
Full Definition of half–life
1 : the time required for half of something to undergo a process: as a : the time required for half of the atoms of a radioactive substance to become disintegrated b : the time required for half the amount of a substance (as a drug, radioactive tracer, or pesticide) in or introduced into a living system or ecosystem to be eliminated or disintegrated by natural processes
2 : a period of usefulness or popularity preceding decline or obsolescence <slang usually has a short half–life>
1907
First Known Use of half–life
1907
HALF–LIFE Defined for Kids
half–life
playDefinition of half–life for Students
half–lives
\-ˌlīvz\: the time required for half of the atoms of a radioactive substance to change composition
Medical Dictionary
half–life
playMedical Definition of half–life
: the time required for half of something to undergo a process: asa: the time required for half of the atoms of a radioactive substance to become disintegratedb: the time required for half the amount of a substance (as a drug or radioactive tracer) in or introduced into a living system or ecosystem to be eliminated or disintegrated by natural processes <the serum half–life is about 2 days—Journal of the American Medical Association>
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Spanish Central: Translation of half–life
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