An Air Sample Is Contaminated with ¹⁵O,which Has a Half-Life

question 28

Multiple Choice

An air sample is contaminated with ¹⁵O,which has a half-life of 2.03 minutes.You can pass it through a long pipe to allow it to decay until it can be safely released into the atmosphere.If the speed of the gas in the pipe is 1.1 m/s,how long must the pipeline be for the sample to decay to 3.0% of its original activity?

• A)680 m
• B)8.0 m
• C)72 m
• D)250 m