Word:

Half-life

Half´-life`   Pronunciation: häf´līf`
n.1.(Physics) the time it takes for one-half of a substance decaying in a first-order reaction to be destroyed. For radioactive substances, it is the time required for one-half of the initial amount of the radioactive isotope to decay. The half-lifeis a measure of the rate of the reaction being observed. For processes that are true first-order processes, such as radioactive decay, the half-life is independent of the quantity of material present, and it is thus a constant. The time it takes for one-half the remaining quantity of a radioactive isotope to decay will be the same regardless of how far the decay process has advanced. Some chemical reactions are also first order, and may be characterized as having a half-life. However, for chemical reactions the half-life will depend upon temperature and in some cases other environmental conditions, whereas for radioactive isotopes the rate of decay is largely independent of the environment.
Noun1.half-life - the time required for something to fall to half its initial value (in particular, the time for half the atoms in a radioactive substance to disintegrate)
Synonyms: half life
half life, period, period of time, time period
Translate Half-life to German, Translate Half-life to French
Browse
Half-decked
half-duplex
Half-faced
Half-fish
half-free morel
half-hardy
Half-hatched
Half-heard
half-heartedly
half-holiday
half-hour
Half-hourly
half-intensity
Half-lattice girder
Half-learned
Half-length
-- Half-life --
half-light
Half-mast
Half-moon
half-pay
Half-pike
half-pint
Half-port
half-price
Half-ray
Half-read
half-relief
Half-round hoop
half-seas-over
Half-sighted
Half-sister
half-size
Definitions Index: # A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

About this site and copyright information - Online Dictionary Home