The Strontium-90 isotope has a half-life of 28.1 years. Supposed we used a .10 Curie sample...
The Strontium-90 isotope has a half-life of 28.1 years. Supposed we used a .10 Curie sample of Sr-90. That is, we used enough Sr-90 to have an activity of .10 Ci (1 Ci=3.7x1010 disintegrations/second)
Calculate the activity of this sample when used by students 281 years from now.
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The Strontium-90 isotope has a half-life of 28.1 years. Supposed
we used a .10 Curie sample...
Strontium-90 has a half-life of 28.1 years. Starting with 3.2 mg of this isotope, how much...
Strontium-90 has a half-life of 28.1 years. Starting with 3.2 mg of this isotope, how much would remain after 112.4 years?
Question 19 Correct Mark 1.00 out of 1.00 By mass spectral analysis, a sample of strontium...
Question 19 Correct Mark 1.00 out of 1.00 By mass spectral analysis, a sample of strontium is known to contain 2.64x1010 atoms of Sr-90 as the only radioactive element. The absolute disintegration rate of this sample is measured as 1238 disintegrations per minute. Calculate the half-life (in years) of Sr-90. P Flag question Answer: 28.1 Question 20 Incorrect How long will it take (in years) for the disintegration rate of this sample to drop to 757 disintegrations per minute? Mark...
Sr-90 has a half-life of 29.1 years. How long will it take for the activity of...
Sr-90 has a half-life of 29.1 years. How long will it take for the activity of a Sr-90 sample to decay from 5.3 times 10^3 dpm (disintegrations per minute) to 3 times 10^2 dpm? The half-life of a radioisotope is 3 d. What percent remains after 1 week?
A 0.0116-g sample of a radioactive isotope with a half life of 1.3x109 years decays at...
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)
Yttrium 90, which has a half-life of 64.2 h, is produced from the fission product strontium...
Yttrium 90, which has a half-life of 64.2 h, is produced from the fission product strontium 90 which has a half-life of 27.5 years. How much Y-90 will be present after I week from a sample of pure Sr-90 in a closed container? Ans.: 0.00027
An isotope of cesium (Cesium-137) has a half-life of 30 years. If 1.0 mg of cesium-137...
An isotope of cesium (Cesium-137) has a half-life of 30 years. If 1.0 mg of cesium-137 disintegrates over a period of 90 years, how many mg of cesium-137 would remain? 14. Thallium-208 has a half-life of 3.053 min. How long will it take for 120.0g to decay to 7.500 15. Element-106 has a half-life of 0.90 seconds. If one million atoms of it were prepared, how many atoms would remain after 4.5 seconds? 16. A 2.5 gram sample of an...
change the answer 10. (0/5 points) DETAILS PREVIOUS ANSWERS The half-life of isotope 228 Th is...
change the answer 10. (0/5 points) DETAILS PREVIOUS ANSWERS The half-life of isotope 228 Th is 1.913 years. Calculate the activity of 7e-069 of this isotope in B and C: 90 A= 362 XBq and A ci. Find the activity of this sample after 8 years: C. Submit Answer View Previous Question Question 10 of 11 View Next Question Home My Assignments Request Extension
9. Strontium-90 has a half-life of 28.8 years and has the same basic chemical properties as...
9. Strontium-90 has a half-life of 28.8 years and has the same basic chemical properties as calcium. The nuclear testing 60 years ago resulted in some small amount of radioactive strontium-90 residing in all of our bones (us old folks, at least). Assuming the contamination remained in the body all those years, calculate the fraction ( N / No ) of that initial contamination still present in our bones. *Please include a diagram
Assume that a hypothetical radioactive isotope has a half-life of 15 years. A 100.0-mCi sample of...
Assume that a hypothetical radioactive isotope has a half-life of 15 years. A 100.0-mCi sample of this radioactive isotope is deposited in a lead container. How long it will take until the activity of this sample is reduced to 1.00 mCi?
the half-life of Sr-90 is 29 years. what fraction if the atoms in a sample Sr-90...
the half-life of Sr-90 is 29 years. what fraction if the atoms in a sample Sr-90 would remain 175 years later?
Strontium-90 has a half-life of 28.1 years. Starting with 3.2 mg of this isotope, how much would remain after 112.4 years?
Question 19 Correct Mark 1.00 out of 1.00 By mass spectral analysis, a sample of strontium is known to contain 2.64x1010 atoms of Sr-90 as the only radioactive element. The absolute disintegration rate of this sample is measured as 1238 disintegrations per minute. Calculate the half-life (in years) of Sr-90. P Flag question Answer: 28.1 Question 20 Incorrect How long will it take (in years) for the disintegration rate of this sample to drop to 757 disintegrations per minute? Mark...
Sr-90 has a half-life of 29.1 years. How long will it take for the activity of a Sr-90 sample to decay from 5.3 times 10^3 dpm (disintegrations per minute) to 3 times 10^2 dpm? The half-life of a radioisotope is 3 d. What percent remains after 1 week?
Yttrium 90, which has a half-life of 64.2 h, is produced from the fission product strontium 90 which has a half-life of 27.5 years. How much Y-90 will be present after I week from a sample of pure Sr-90 in a closed container? Ans.: 0.00027
An isotope of cesium (Cesium-137) has a half-life of 30 years. If 1.0 mg of cesium-137 disintegrates over a period of 90 years, how many mg of cesium-137 would remain? 14. Thallium-208 has a half-life of 3.053 min. How long will it take for 120.0g to decay to 7.500 15. Element-106 has a half-life of 0.90 seconds. If one million atoms of it were prepared, how many atoms would remain after 4.5 seconds? 16. A 2.5 gram sample of an...
change the answer 10. (0/5 points) DETAILS PREVIOUS ANSWERS The half-life of isotope 228 Th is 1.913 years. Calculate the activity of 7e-069 of this isotope in B and C: 90 A= 362 XBq and A ci. Find the activity of this sample after 8 years: C. Submit Answer View Previous Question Question 10 of 11 View Next Question Home My Assignments Request Extension
Assume that a hypothetical radioactive isotope has a half-life of 15 years. A 100.0-mCi sample of this radioactive isotope is deposited in a lead container. How long it will take until the activity of this sample is reduced to 1.00 mCi?
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