<Dl> <Dd> <Ul> <Li> N is the initial quantity of the substance that will decay ( this quantity may be measured in grams , moles , number of atoms , etc . ) , </Li> <Li> N ( t ) is the quantity that still remains and has not yet decayed after a time t , </Li> <Li> t is the half - life of the decaying quantity , </Li> <Li> τ is a positive number called the mean lifetime of the decaying quantity , </Li> <Li> λ is a positive number called the decay constant of the decaying quantity . </Li> </Ul> </Dd> </Dl>
<Dl> <Dd> <Ul> <Li> N is the initial quantity of the substance that will decay ( this quantity may be measured in grams , moles , number of atoms , etc . ) , </Li> <Li> N ( t ) is the quantity that still remains and has not yet decayed after a time t , </Li> <Li> t is the half - life of the decaying quantity , </Li> <Li> τ is a positive number called the mean lifetime of the decaying quantity , </Li> <Li> λ is a positive number called the decay constant of the decaying quantity . </Li> </Ul> </Dd> </Dl>
formula for calculating half life of a radioactive substance
formula for calculating half life of a radioactive substance
N ( t ) is the quantity that still remains and has not yet decayed after a time t , t is the half - life of the decaying quantity ,
N ( t ) is the quantity that still remains and has not yet decayed after a time t , t is the half - life of the decaying quantity ,