The half-life of strontium-90 is 28.1 years. How long will it take a 10.0-g sample of strontium-90 to decompose to 0.69 g?
a) 217 years
b) 108 years
c) 163 years
d) 73 years
The half-life of strontium-90 is 28.1 years. How long will it take a 10.0-g sample of...
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?
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.
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?
(4 points) The half-life of radioactive strontium-90 is approximately 32 years. In 1964, radioactive strontium-90 was released into the atmosphere during testing of nuclear weapons, and was absorbed into people's bones. How many years does it take until only 9 percent of the original amount absorbed remains? time = 1 years
Ch.20 #9
Enter your answer in the provided box. Strontium-90 is one of the products of the fission of uranium-235. This strontium isotope is radioactive, with a half-life of 28.1 years. Calculate how long (in years) it will take for 8.93 g of the isotope to be reduced to 0.430 g by decay. yr
Rhodium-101 has a half life of 3.3 years. How long will it take for a sample of rhodium-101 to decay so that there is only 1/16 of it left?
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
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...
Be sure to answer all parts. 90Sr.( The half-life of strontium-90 is 29.1 years. Calculate the radioactivity in millicuries of 16.4 mg of 90Sr = 89.908 g/mol) Enter your answer in scientific notation. X 10! mCi
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...