In a laboratory accident a work area is contaminated with ...

[xroflmao]

In a laboratory accident a work area is contaminated with radioactive material. Health physicists monitor the area during a 30-day period and, after correcting for the background rate, obtain the data shown in the table.
 
  Time (days) 0 2 6 11 19 30
  Counts/min 1000 899 727 557 364 202
 
  The accident occurred at t = 0. They determine that it will not be safe for workers to enter the area until the radioactivity level has dropped to 133 counts per minute. Of the choices listed below, which one is the earliest time that workers could safely return?
  A) 38 days
  B) 44 days
  C) 50 days
  D) 32 days
  E) 24 days

Question 2

An isotope of Tc having a half-life of 6.0 h is used in bone scans. If a certain amount of this Tc is injected into the body, how long does it take for its initial decay rate to decrease BY 99?
 
  A) 0.060 h
  B) 3.3 h
  C) 33 h
  D) 40 h
  E) slightly more than a month

[olivia_paige29]

Answer to Question 1

Answer: A

Answer to Question 2

Answer: D

[xroflmao]

Thanks

[olivia_paige29]

Welcome