The half-life of the radioactive substance is given by T = 0.693/λ The average life or the mean life of the substance is given by τ= 1/λ λ is the decay constant.
What is the correct relation between half-life and average life?
It turns out that the mean life equals the half life divided by the natural logarithm of 2 (about 0.693) . The mean life also turns out to exactly equal the number τ that appears in the exponential term e − t / τ involved with describing decay or growth, called the time constant.
Is mean life equal to half-life?
The mean life of an element equals the half-life of the substance divided by the natural logarithm of 2 which is about 0.693. In fact, the mean life turns out to equal the number τ which appears in the exponential term e − t / τ involved in the description of decay or growth. It is termed as the time constant.
What is the relation between half-life and mean life of radioactive element?
Note – Half-life of a radio-active substance is defined as the time over the nuclei of half of the atoms of a radioactive substance completely decays . Mean life of a radioactive substance is the average life of all the nuclei of the atoms present in that substance that undergoes radioactive decay.
What is the relation between mean life and decay constant?
The mean life (τ) of a radioactive substance is equal to reciprocal of decay constant . It is the process in which a heavy nucleus splits up into two nuclei of nearly comparable masses.
What Causes half-life?
A half-life is the time taken for something to halve its quantity. The term is most often used in the context of radioactive decay , which occurs when unstable atomic particles lose energy. Twenty-nine elements are known to be capable of undergoing this process.
How do you calculate half-life?
The time taken for half of the original population of radioactive atoms to decay is called the half-life. This relationship between half-life, the time period, t 1 / 2 , and the decay constant λ is given by t12=0.693λ t 1 2 = 0.693 λ . Break down tough concepts through simple visuals.
What is meant by half-life time?
Half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy) , or, equivalently, the time interval required for the number of disintegrations per second of a radioactive ...
What is the formula of average life?
To calculate the average life, multiply the date of each payment (expressed as a fraction of years or months) by the percentage of total principal that has been paid by that date, add the results, and divide by the total issue size . Then divide the weighted total by the bond face value to get the average life.
What is the average life of radioactive element?
The average life or the mean life of a radioactive substance is given by the ratio of the total lifetime of all the individual parent atoms to the total number of such atoms present in the sample .
What is activity of radioactive sample?
Activity, in radioactive-decay processes, the number of disintegrations per second, or the number of unstable atomic nuclei that decay per second in a given sample .
What does decay constant depends on?
The decay constant depends only on the particular radioactive nuclide and decay mechanism involved . It does not depend on the number of nuclei present or on any external conditions (such as temperature).
What is the SI unit of decay constant?
Probability of a given nucleus in a particular energy state undergoing a spontaneous nuclear transition from that energy state in a unit time interval. The SI unit of decay constant is s-1 .
How does half-life work?
The half-life of a drug is an estimate of the period of time that it takes for the concentration or amount in the body of that drug to be reduced by exactly one half (50%). ... For example, if 100mg of a drug with a half-life of 60 minutes is taken, the following is estimated: 60 minutes after administration, 50mg remains.
