mean life, in radioactivity, average lifetime of all the nuclei of a particular unstable atomic species. This time interval may be thought of as the sum of the lifetimes of all the individual unstable nuclei in a sample, divided by the total number of unstable nuclei present.
What do you mean by average life?
What Is Average Life? The average life is the length of time the principal of a debt issue is expected to be outstanding. Average life does not take into account interest payments, but only principal payments made on the loan or security.
What is average life of radioactive decay?
The average life of any radioactive isotope has equaled the half-life of the substance divided by the natural log 2 which is exactly 0.693, and it’s equal to the number of τ which is represented in the exponential term e−t/τ in the decaying. It is called the time constant.
What are half-life and average life of radioactive nucleus?
(a) Half-life of a radioactive nucleus is the time taken for the nuclear to reduce to half of its initial value. That is, where λ is the decay constant. Average life or mean life of radioactive nucleus is defined as the ratio of total lifetime of radioactive atoms to the total number of atoms in the sample.
What is average life obtain the equation of average life?
Average life time `(tau)` is equal to the total life time of all the `N_(0)` nuclei divided by the total number of original nuclei `N_(0)`.
4. Average life `tau = (int ” t dN”)/(N_(0))`
But `(dN)/(dt)= – lambda N`
`dN= – lambda N dt = N_(0)e^(-lambda t)dt [because N = N_(0) e^(-lambda t)]`
Are mean life and average life same?
Solution : Mean life: The average time for which the nuclei of atoms of radioactive substance exist is called average life.
What is meant by half-life and average life of radioactive element?
Average life: The average 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 nuclei. Half-life: Half-life is the time during which half the number of radioactive atoms present initially in the sample of element decay.
What is average life Quora?
One whose life is dedicated for the wellness and survival of his/her loved ones.
Why is it called half-life?
In biology, a half-life is the time taken for a substance to lose half its effects. The most obvious instance is drugs; the half-life is the time it takes for their effect to halve, or for half of the substance to leave the body.
What is the definition of a half-life?
Definition of half-life 1 : the time required for half of something to undergo a process: such as. a : the time required for half of the atoms of a radioactive substance to become disintegrated.
What is the unit of half-life?
Explanation: The units of half-life are time. The half-life is the length of time that it takes for half of an initial sample to undergo a change. Usually this is the radio-active decay of a specific atomic weight of an element.
Which of the following is correct for average life?
The average life is the average time up to which the unstable nuclei exist. Was this answer helpful?
Average life is reciprocal of Half life of radioactive substance.
What is the relation between average life and decay constant of radioactive substance?
Relation between average life and decay constant T=γ1.
Who discovered half-life?
The original term, half-life period, dating to Ernest Rutherford’s discovery of the principle in 1907, was shortened to half-life in the early 1950s.
What is half-life in nuclear physics?
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 …
Why is half-life not full life?
The term half-life is appropriate due to the exponential and quantum nature of radioactive decay, which makes it impossible to predict exactly when a single atom of radioactive material will disintegrate.
What is mean by average life of a radioactive element derive an expression for it?
Solution : Average life. The average life of a radioactive substance is the ratio of sum of lives of all the atoms to the total number of atoms. < br> `”Average life”=(“Sum of lives of all the atoms”)/(“Total number of atoms”)`
Since `N=N_(0)e^(-lambda t)`
`:. dN= – lambda N_(0)e^(-lambda t) dt`. <
How do you calculate half-life physics?
What is relation between mean life and decay constant?
Solution : `t=(1)/(lambda)` where `t rarr` mean life , `lambda rarr` decay constant.
What is the difference between half-life and radioactivity?
The radioactive decay of a certain substance is measured by a special term known as the half life. The time taken by a substance to become half of its initial mass through radioactive decay is measured as the half life of that substance. This is the relationship between radioactive decay and half life.
What is half-life and decay constant?
The time required for half of the original population of radioactive atoms to decay is called the half-life. The relationship between the half-life, T1/2, and the decay constant is given by T1/2 = 0.693/λ.
How long can human lives?
While most of us can expect to live to around 80, some people defy expectations and live to be over 100. In places such as Okinawa, Japan and Sardinia, Italy, there are many centenarians. The oldest person in history – a French woman named Jeanne Calment – lived to 122.
Is it okay to hope for an average life?
They found those with more hope throughout their lives had better physical health, better health behaviors, better social support and a longer life. Hope also led to fewer chronic health problems, less depression, less anxiety and a lower risk of cancer.
How much should a person live?
The average global life expectancy from birth is 72 – that’s 70 for men and 75 for women. However, this changes with age. For example, somebody aged 69 may expect to live another 17 years on average.