After 70 years, 40 % of a radioactive material decays. What is the half-life?
After 70 years, 40 % of a radioactive material decays. What is the half-life?
a. what is the half life of a radioactive isotope if a 32.0g sample decays to 24.6g after 127 days? b. 76Kr has a half-life of 14.8 hours. How long will it take for 75% of the sample to decay?
A sample of radioactive material is initially found to have an activity of 115 decays/min. After 4 d 22 h, its activity is measured to be 63 decays/min. 1) (a) Calculate the half-life of the material.
These questions are about radioactive half-life.
22. 256 grams of a radioactive sample decays to 4 grams in 120
minutes. What is the half life of the sample?
These questions are about radioactive half-life 22. 256 grams of a radioactive sample decays to 4 grams in 120 minutes. What is the half life of the sample? 22.
These questions are about radioactive half-life.
22. 256 grams of a radioactive sample decays to 4 grams in 120
minutes. What is the half life of the sample?
These questions are about radioactive half-life. 22. 256 grams of a radioactive sample decays to 4 grams in 120 minutes. What is the half life of the 22. sample?
A radioactive element decays with a half-life of 100 years. If there are 10 grams of this element today, how many grams will remain 50 years from now? - O A 10 V OBS 15 Ос. 2 D. 10/2 O E. 10 Reset Selection
A) A radioactive material produces 1220 decays per minute at one time, and 4.2 h later produces 150 decays per minute. What is its half-life? B) What fraction of a sample of 6832Ge, whose half-life is about 9 months, will remain after 3.5 yr ? C) What is the activity of a sample of 146C that contains 7.0×1020 nuclei? The half-life of 146C is 5700 years.
A 0.0116-g sample of a radioactive isotope with a half life of 1.3x109 years decays at the rate of 2.9x104 disintegrations per minute. Calculate the molar mass of the isotope. Enter your answer in scientific notation. (g/mol)
(X) A radioactive material decays at a rate proportional to the population present at time t. After 6 hours, the material has decreased by 87.5% (remained 12.5%). What is the half-life of this material? 24 a) d) 2 c) b) 4
91. If the half – life of a sample of radioactive material is 60 days, what fraction of the original radioactive nuclei will remain after 120 days.
Certain radioactive material decays in such a way that the mass remaining after t years is given by the function m(t) = 180e -0.045 where m(t) is measured in grams. (a) Find the mass at time t = 0. Your answer is (b) How much of the mass remains after 50 years? Your answer is Round answers to 1 decimal place.