The half-life of a particular radioactive
substance is 1 year. If you started with
40 grams of this substance, how much
of it would remain after 3 years?
Remaining Amount =
[?] grams
Round your answer to the nearest whole number.

After 3 years, the substance will have undergone three half-lives since the half-life is 1 year. Each half-life will halve the amount of the substance:

1st year: 40 grams → 20 grams
2nd year: 20 grams → 10 grams
3rd year: 10 grams → 5 grams

So, after 3 years, you will have approximately 5 grams of the radioactive substance remaining.

Looking at real-life examples, understanding half-lives helps us grasp many scientific fields such as archaeology, where carbon dating uses the concept to determine the age of ancient artifacts, or medical applications in assessing the decay of radioactive tracers used in imaging techniques. It’s fascinating how this fundamental concept has practical implications!

On another note, when tackling half-life problems, a common mistake is forgetting to count the number of half-lives correctly or miscalculating the remaining amount at each stage. A great tip is to remember that the amount decreases exponentially; using a diagram can help visualize the decay process!