Ask Question
3 September, 09:17

The half life of a certain radioactive element is 800 years. How old is an object if only 12.5% of radioactive atoms in it remains?

+3
Answers (1)
  1. 3 September, 11:39
    0
    Given, half life of a certain radioactive element = 800 years.

    Amount of substance remaining at time t = 12.5%

    Lets consider the initial amount of the radioactive substance = 100%

    Using the half life equation:

    A = A₀ (1/2) ^t/t₁/₂

    where A₀ is the amount of radioactive substance at time zero and A is the amount of radioactive substance at time t, and t₁/₂ is the half-life of the radioactive substance.

    Plugging the given data into the half life equation we have,

    12.5 = 100. (1/2) ^t/800

    12.5/100 = (1/2) ^t/800

    0.125 = (0.5) ^t/800

    (0.5) ^3 = (0.5) ^t/800

    3 = t/800

    t = 2400 years

    Thus the object is 2400 years old.
Know the Answer?
Not Sure About the Answer?
Get an answer to your question ✅ “The half life of a certain radioactive element is 800 years. How old is an object if only 12.5% of radioactive atoms in it remains? ...” in 📙 Chemistry if there is no answer or all answers are wrong, use a search bar and try to find the answer among similar questions.
Search for Other Answers