Use the fact that the quantity of a radioactive substance after t years is given by where is the original amount of radioactive material and k is its half-life (the number of years it takes for half the radioactive substance to decay). The half-life of strontium-90 is 25 years. Find the amount of strontium-90 remaining after 7 years if . Round your answer to one decimal place.

A)8.1 kg
B)79.1 kg
C)5.8 kg
D)116.6 kg
E)0.8 kg

Question

Use the fact that the quantity of a radioactive substance after t years is given by  where  is the original amount of radioactive material and k is its half-life (the number of years it takes for half the radioactive substance to decay). The half-life of strontium-90 is 25 years. Find the amount of strontium-90 remaining after 7 years if  . Round your answer to one decimal place.
​
A)8.1 kg 
B)79.1 kg 
C)5.8 kg 
D)116.6 kg 
E)0.8 kg

Quizplus · Accepted Answer

The Answer of Use the fact that the quantity of a radioactive substance after t years is given by  where  is the original amount of radioactive material and k is its half-life (the number of years it takes for half the radioactive substance to decay). The half-life of strontium-90 is 25 years. Find the amount of strontium-90 remaining after 7 years if  . Round your answer to one decimal place.
​
A)8.1 kg 
B)79.1 kg 
C)5.8 kg 
D)116.6 kg 
E)0.8 kg

Use the Fact That the Quantity of a Radioactive Substance