Question

A 2000g sample of radioactive material has a half-life of 14 years. How much should remain after 42 years?

A. 500g
B. 750g
C. 1000g
D. 1500g

Answer 1

After 42 years, there should remain 250g of the radioactive material.

Step-by-step explanation:

To find out how much radioactive material remains after a certain period of time, we can use the concept of half-life. The half-life is the time it takes for half of the radioactive material to decay. In this case, the half-life is 14 years. After 42 years, which is three times the half-life, we can divide the initial amount of the sample by 2 three times to find the remaining amount:

Initial amount: 2000g

After 14 years: 2000g / 2 = 1000g

After 28 years: 1000g / 2 = 500g

After 42 years: 500g / 2 = 250g

Therefore, after 42 years, there should remain 250g of the radioactive material.