chemistry

Fluorine-20 has a half-life of 11.0 s. If a sample initially contains 49.0 μg of this isotope, how much remains after 66.0 s ?

  1. 0
  2. 0
  3. 6
asked by susan
  1. 66s is 6 half-lives, so

    49.0 * (1/2)^6 = 0.765 μg

    1. 0
    2. 0
    posted by Steve

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    Fluorine-18, which has 1/2 life of 110 minutes, is used in PET scans. If 100 mg of fluorine-18 is shipped @8AM, how many milligrams of the radioisotope are still active if the sample arrives at the lab at 1:30 pm?
  2. Chem 3A

    please help me with this chemistry problem. Half-Life A radium-226 sample initially contains 0.112 mol. How much radium-226 is left in the sample after 6400 years? The half-life of radium-226 is 1600 years.
  3. Chemistry

    Gallium65, a radioactive isotope of gallium, decays by first order-kinetics. The half-life of this isotope is 15.2 min. How long would it take for 7/8 of a sample of this isotope to decay? 15.2 min 30.4 min 45.6 min 48.0 min I'm
  4. chemistry

    How long will it take for 25% of the C-14 atoms in a sample of C-14 to decay? The half-life for the radioactive decay of C-14 is 5730 years. If a sample of C-14 initially contains 1.1 mmol of C-14 , how many millimoles will be
  5. physics

    Radioactive nuclei are produced in an irradiated sample at the rate of 10 s-1. If the number in the sample builds up to a maximum of 1000, calculate the mean life and the half-life of the radioactive nuclei Using dN / dt = P - λ
  6. chemistry

    fluorine-18 half life of 110 min if 100mg was shipped at 8:00 am how many mg are still active at 1;30 pm same day
  7. Chemistry

    Upon decomposition, one sample of Magnesium Fluoride produced 1.65 kg of magnesium and 2.57 kg of fluorine. A second sample produces 1.33 kg of magnesium. How much fluorine (in grams) did the second sample produce?
  8. Chemistry

    Which radioactive sample would contain the greatest remaining mass of the radioactive isotope after 10 years? A. 2.0 grams of 198 Au B. 2.0 grams of 42 K C. 4.0 grams of 32 P D. 4.0 grams of 60 Co By the way the numbers next to
  9. physics

    If the physical half-life of sulfur-35 is 87.1 days, and the biologic half-life in the testicle is 632 days, what is its effective half-life in this organ? I know i have to find the time and then the half-life. But im having
  10. Chemistry (Dr.Bob222)

    The half-life of P-32 is 14 days. How long after a sample is delivered can a laboratory wait to use a sample in an experiment if they need at least 10 percent of the original radioactivity? I need help on how to set up this

More Similar Questions