How long will it take a sample of molybdenum-99 (half-life 67 hours) to decay to 25% of its original activity?
Half life period is the time required to a radioactive compound to reduce it to its half value.
t1/2 = 67 hrs
25% of original amount means 1/4 th of the initial amount.
suppose 100 gm molybdenum-99 compound is present, after 67 hrs, compound will reduce to 50 gm
Further 50 gm of compound will undergo decay to its half value in 67 hrs.
In two half cycles compound will be reduced to 1/4 th of its initial amount
hence molybdenum will decay to its 25% in (67+67 = 134 hrs)
How long will it take a sample of molybdenum-99 (half-life 67 hours) to decay to 25%...
The half-life for the radioactive decay of C-14 is 5730 years. How long will it take for 25% of the C-14 atoms in a sample of C-14 to decay. If a sample of C-14 initially contains 1.5 mmol of C-14, how many mmols will be left after 2255 years.
How long will it take a sample of radioactive substance to decay to half of its original amount, if it decays according to the function A(t) = 200e^-0.131t, where t is the time in years? Roud to the nearest hundredth year.
How long will it take a sample of radioactive substance to decay to half of its original amount, if it decays according to the function A(t) = 250e - 223, where t is the time in years? Round your answer to the nearest hundredth year. A) 3.11 yr B) 55.75 yr 24.76 yr D) 27.87 yr
A certain radioactive nuclide has a half life of 50.7 years. How long does it take for 87.5% of a sample of this substance to decay? years Submit Hide Hints Hint 1 Hint 4 Hint 3 Hint 2 What percentage of the original sample has decayed after two half lives have elapsed?
Phosphorus-32, a radioisotope used in leukemia therapy, has a half-life of 14.26 days. How long will it take for a sample of 32P to decay to 18.3% of its original activity? O 3.5 days 4.2 days 15 days 35 days O 17.5 days
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?
How long (in hours) will it take for 99% ofthe technetium 99-m to have decayed after an initial dose. (Half life is 6 hours). 20) a. 48.0 hours b. 40.0 hours c. 20.0 hours d. 1.11 hours e. 0.087 hours
The half-life for the radioactive decay of C−14 is 5730 years. A) How long will it take for 30% of the C−14 atoms in a sample of C−14 to decay? B) If a sample of C−14 initially contains 1.9 mmol of C−14, how many millimoles will be left after 2280 years?
The half life of cobalt 60 is 5.3 years. How long will it take a 4.8g sample of Co60 to decay until only 1.6g of Co60 remains in the sample?
The decay of antimony-131 is first order with a half life is 23.03 minutes. How long (in minutes) would it take for a 1.4100 g sample to be reduced to 0.0893 g?