1. What is a becquerel?
One decay per second
2. What is the half-life of a radioactive isotope?
The time that it takes for half of the parent nuclei to decay
3. A substance has a half-life of 3 hours.
What fraction of the atoms will have decayed after 6 hours?
3/4 of the atoms will have decayed
4. A radioactive substance activity falls from 8,000 counts per minute to 500 counts per minute in 20 hours. What is the half-life of the substance?
5. After the 3rd half-life, how much of the sample is left?
25% | 11/4 | 0.25
6. After the second half-life, how much of the sample is left?
50% | 1/2 | 0.5
7. What does the beta particle have a charge of?
8. If Carbon-14 has a half-life of 5,730 years, how old is a fossil if it has undergone 4 half-lives?
22,920 years old
9. If Carbon-12 has a half-life of 5,730 years, how old is a fossil if it has undergone 7 half-lives?
40,110 years old
10. An isotope has a half-life of 6 hours, what percentage of the isotope will be left after 24 hours?