Question

What is the half-life decay formula ?

Answer 1

Half-life :

1. The time it takes for a substance's radioactivity to decline to half of its original value.
2. The half-life of a radioactive substance does not depend on the amount of the substance initially taken into consideration.

Half-life decay formula :

1. The half-life of the radioactive substance is given by the formula.
   $T_{1/2}=\frac{0.693}{\lambda }$
   $T_{1/2}$ is the half-life of the radioactive substance
   $\lambda$ is the decay constant of the radioactive substance.
2. The decay constant is the probability of decay per unit of time.

Hence the half-life decay formula is $T_{1/2}=\frac{0.693}{\lambda }$.