ecause of its chemical similarity to calcium, Sr can collect in the bones and present a health risk. What percentage Sr present initially still exists after 47.5 y?(The half life of Sr is 28.8 years) 38 % ssfor 60 09Jss f60 ssf

44. A nuclear power plant accident exposes a population of 24,000 people to an A. 0.38 person-Sv B. 0.38 man-rem C. 220 person-Sv average effective dose of 9.2 mSv. What is the collective effective dose? D. 220 man-rem

A 228Th source is labeled 1.50 mCi, but its present activity is found to be 1.73 ✕ 106 Bq. A.)  What is the present activity in mCi? =______mCi B.) How long ago did it actually have a 1.50-mCi activity? =_____y

What mass of fluorine -18. (F-18) is an activity of 10mCi? How long will it take for the activity to decrease to 0.15mCi?

After production, a 300µl solution with a specific activity of 50 GBq/ml was torn. Delivery timeis 1 day. The half-life of the isotope is 4 days. Find the amount of solution that needs to besent so that the customer has 3.0 GBq at the date of delivery.

In 1992, Swiss police arrested two men who were attempting to smuggle osmium out of Eastern Europe for a clandestine sale. However, by error, the smugglers had picked up 137Cs. Reportedly, each smuggler was carrying a 1.0 g sample of 137Cs in a pocket! In (a) bequerels and (b) curies, what was the activity of each sample? The isotope 137Cs has a half-life of 30.2 y. (The activities of radioisotopes commonly used in hospitals range up to a few millicuries.)

14 A sample has a ¹4C activity of 0.0027 Bq per gram of carbon. (a) Find the age of the sample, assuming that the activity per gram of carbon in a living organism has been constant at a value of 0.23 Bq. (b) Evidence suggests that the value of 0.23 Bq might have been as much as 27% larger. Repeat part (a), taking into account this 27% increase. (a) Number i (b) Number i Units Units