Effective half-life - Citizendia

For other uses, see Half-life (disambiguation).

Effective half-life denotes the halving of radioactive material in a living organism by means of radioactive decay and biological excretion. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Excretion is the process of eliminating waste products of Metabolism and other non-useful materials A decay constant is needed to calculate the half-life. A quantity is said to be subject to exponential decay if it decreases at a rate proportional to its value Half-Life (computer-game page here It's already listed in the disambiguation page It is the sum of the biological and physical decay constants, as in the formula:

${\lambda_e} \, = {\lambda_p} \, + {\lambda_b} \,$

With the decay constant it is possible to calculate the effective half-life using the formula:

$t_{1/2} = \frac{\ln (2)}{\lambda_e}$

The biological decay constant is often approximated as it is more difficult to accurately determine than the physical decay constant.

External links

Biological Half-life

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