What is the number of half life periods required for a sample of a radioactive material?
What is the number of half life periods required for a sample of a radioactive material?
Half-life (t1/2) is the time required for one half of the nuclei in a sample of radioactive material to decay. After each half-life has passed, one half of the radioactive nuclei will have transformed into a new nuclide (see table below).
What is the number of nuclei remaining after n half life periods?
Half-life
| Number of half-lives elapsed | Fraction remaining | Percentage remaining |
|---|---|---|
| 6 | 1⁄64 | 1 |
| 7 | 1⁄128 | 0 |
| … | … | … |
| n | 1⁄2n | 100⁄2n |
What is the half life of a radioactive nuclide?
The half life of radioactive nuclides is defined as the time in which half of the original number of radioactive atoms has decayed. Example: Imagine you start with 100 atoms of nuclide X. X decays to nuclide Y with a half life of 10 days.
How is radioactive half life determined?
The half-life is then determined from the fundamental definition of activity as the product of the radionuclide decay constant, λ, and the number of radioactive atoms present, N. One solves for λ and gets the half-life from the relationship λ = ln2/T1/2.
How do you find the number of nuclei in a sample?
The number of nuclei N as a function of time is N =N0e−λt, where N0 is the number present at t = 0, and λ is the decay constant, related to the half-life by \(\lambda=\frac{0.693}{t_{1/2}}\\\).
Which isotope has the shortest half-life rubidium 87 lead 214 Uranium 238 Carbon-14?
Out of the options given above, lead-214 is the element with the shortest half-life.
What of the substance remains after the nuclide decays for 14 hours if the half-life of the nuclide is 28 days?
Half-life plot (video) | Nuclei | Khan Academy.