Half-life

Half-life

The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. In a medical context, the half-life may also describe the time that it takes for the concentration of a substance in blood plasma to reach one-half of its steady-state value. The converse of half life is doubling time, which is the same as doubling the time a quantity takes to decay.

About Half-life in brief

Summary Half-lifeHalf-life is the time required for a quantity to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for the exponential decay equation. In a medical context, the half-life may also describe the time that it takes for the concentration of a substance in blood plasma to reach one-half of its steady-state value.

In epidemiology, the concept of half- life can refer to the length of time it takes to dissipation from plants and certain pesticides. The concept of a half-lives of a biological substance can also be used to describe its elimination from the human body, for example, the amount of caesium in a human body is between one and four months. The converse of half life is doubling time, which is the same as doubling the time a quantity takes to decay from its initial state to its current state.