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The activity of a freshly prepared radioactive sample is 1010 disintegrations per second, whose mean life is
109 s. The mass of an atom of this radioisotope is 10-25 kg. The mass (in mg) of the radioactive sample is
    Correct answer is '1'. Can you explain this answer?
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    The activity of a freshly prepared radioactive sample is 1010 disinteg...
    Mass of the Radioactive Sample

    Given:
    Activity (A) = 10^10 disintegrations per second
    Mean life (τ) = 10^9 s
    Mass of an atom (m) = 10^-25 kg

    We need to find the mass of the radioactive sample in milligrams (mg).

    ### 1. Finding the Decay Constant (λ)

    The decay constant (λ) is related to the mean life (τ) by the formula:

    λ = 1 / τ

    Substituting the given value of τ:

    λ = 1 / (10^9 s)
    λ = 10^-9 s^-1

    ### 2. Finding the Number of Atoms (N)

    The activity (A) is defined as the number of disintegrations per second. It is related to the decay constant (λ) and the number of radioactive atoms (N) by the formula:

    A = λN

    Rearranging the formula to solve for N:

    N = A / λ

    Substituting the given values of A and λ:

    N = (10^10 disintegrations per second) / (10^-9 s^-1)
    N = 10^19 radioactive atoms

    ### 3. Finding the Mass of the Sample (M)

    The mass of the sample (M) is related to the number of atoms (N) and the mass of a single atom (m) by the formula:

    M = N * m

    Substituting the given values of N and m:

    M = (10^19 radioactive atoms) * (10^-25 kg/atom)
    M = 10^-6 kg = 1 mg

    ### Conclusion

    The mass of the radioactive sample is 1 milligram (mg).
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    The activity of a freshly prepared radioactive sample is 1010 disintegrations per second, whose mean life is109 s. The mass of an atom of this radioisotope is 10-25 kg. The mass (in mg) of the radioactive sample isCorrect answer is '1'. Can you explain this answer?
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    The activity of a freshly prepared radioactive sample is 1010 disintegrations per second, whose mean life is109 s. The mass of an atom of this radioisotope is 10-25 kg. The mass (in mg) of the radioactive sample isCorrect answer is '1'. Can you explain this answer? for JEE 2025 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about The activity of a freshly prepared radioactive sample is 1010 disintegrations per second, whose mean life is109 s. The mass of an atom of this radioisotope is 10-25 kg. The mass (in mg) of the radioactive sample isCorrect answer is '1'. Can you explain this answer? covers all topics & solutions for JEE 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The activity of a freshly prepared radioactive sample is 1010 disintegrations per second, whose mean life is109 s. The mass of an atom of this radioisotope is 10-25 kg. The mass (in mg) of the radioactive sample isCorrect answer is '1'. Can you explain this answer?.
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