If we have "N₀" number of any radioactive element then after a period of "n" half-lives the number of atoms left behind is:
Correct answer: B. (1/2)nN0
- A. 2ⁿN₀
- B. (1/2)nN0
- C. (½ N₀)ⁿ
- D. (2N₀)ⁿ
Explanation
A half-life is the time it takes for half of the radioactive substance to decay.After one half-life, half of the original quantity remains, so there will be N0\ .2After two half-lives, half of the remaining half will decay, leaving N0\4Continuing this process, after "n" half-lives, the remaining quantity can be expressed as:N=N0(1/2)nThis means that the number of atoms left after "n" half-lives is (1/2)nN0
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