At the start of an experiment, there are 120,000 undecayed radioactive nuclei in a sample. After 8 hours, there are 7,500 undecayed nuclei in the sample. What is the half-life of the sample?

Question

4 hours
2 hours
8 hours
1 hour

Answer 1

The half-life of a radioactive substance is the amount of time it takes for half of the nuclei in a sample to decay.

In this case, we can see that the number of undecayed nuclei has decreased from 120,000 to 7,500 in 8 hours.

This means that half of the original number of undecayed nuclei (60,000) has decayed in 8 hours. Therefore, the half-life of the sample is 8 hours.

So, the correct answer is 8 hours.