Chemistry

posted by .

The half-life for beta decay of strontium-90 is 28.8 years. A milk sample is found to contain 10.3 ppm strontium-90. How many years would pass before the strontium-90 concentration would drop to 1.0 ppm?

  • Chemistry -

    k = 0.693/t1/2
    Substitute k into the equation below.
    ln(No/N) = kt
    No = 10.3 ppm
    N = 1.0 ppm
    k from above.
    t = ?

  • Chemistry -

    DR.BOB222 ENGLISH PLEASE?????? I know how to get the beta decay for strontium. just having a hard time with the concentration of strontium and the amount of yrs. passed....please help!!

  • Chemistry -

    All you need to do is to substitute 28.8 years into equation 1 I gave you to solve for k, then substitute k into the
    ln(No/N) = kt and solve for t.
    I TOLD you what to substitute for No and I told you what to substitute for N and k. You have only to solve for t. t is approximately 100 years for the Sr to decay to about 1.0 ppm.

  • Chemistry -

    the half-life of cobalt-60 is 5.20 years.. how many milligrams of a 2.000-mg sample remains after 6.55 years?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. AP Environmental Science (URGENT)

    Strontium-90 is a radioactive waste product from nuclear reactors. It has a half-life of 29 years. How many years will it take for a quantity of strontium-90 to decay to 1/16 (one-sixteenth) of its original mass?
  2. chemistry

    Strontium-90 decays through the emission of beta particles. It has a half-life of 29 years. How long does it take for 80% of a sample of strontium-90 to decay?
  3. chem

    Radioactive substances decay by first-order kinetics. How many years would be required for a sample containing strontium-90 to decrease to 58.32% of its initial activity?
  4. Math

    Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the …
  5. calculus

    Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the …
  6. SCIENCE

    We did a radioactive decay and half life lab with m&ms and I do not understand these conclusion questions: 1. how many half lives would it take for 500 nuclei to decay to 6.25% of the original number of nuclei?
  7. Science

    Can anyone help me find the half-life of strontium-90?
  8. Forensics

    Strontium-90 is a radioactive waste product from nuclear reactors. It has a half life of 29 years. How many years would it take for a quantity of strontium-90 to decay 1/16 of its original mass?
  9. Math

    The element strontium-90 is radioactive. The percent of strontium -90, A(t), left in a sample can be modelled by the half-life function A(t) = A0 (1/2)^t/29, where t represents the time, in years, after the initial time, and A0 represents …
  10. math

    Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t)=(.98)^t (b) Estimate …

More Similar Questions